KR20140111992A - Chemical mechanical planarization for tungsten-containing substrates - Google Patents

Abstract

Disclosed in the present invention is a chemical mechanical polishing (CMP) composition for polishing tungsten or a tungsten-containing substrate, which comprises a polisher; at least one solid catalyst; a chemical additive selected from a piperazine derivative, a cyanate salt, and a combination of the same; and a liquid carrier. An aqueous formulation for polishing tungsten or a tungsten-containing substrate is used in a system and a method.

Description

CHEMICAL MECHANICAL PLANARIZATION FOR TUNGSTEN-CONTAINING SUBSTRATES FOR TUNGSTEN-

Cross-reference to related application

This application claims priority to U.S. Provisional Application No. 61 / 777,165, filed March 12, 2013, which is incorporated herein by reference in its entirety for all permissible purposes.

The present invention generally relates to chemical-mechanical planarization (CMP) of tungsten-containing substrates on semiconductor wafers.

BACKGROUND OF THE INVENTION [0002] A large number of materials are used in the fabrication of integrated circuits such as semiconductor wafers. The materials are generally classified into three categories: dielectric material, adhesion and / or barrier layer, and conductive layer. Dielectric materials such as various substrates such as TEOS, plasma-enhanced TEOS (PETEOS), and low-k dielectric materials; Barrier / adhesion layers such as tantalum, titanium, tantalum nitride, and titanium nitride; And the use of conductive layers such as copper, aluminum, tungsten, and noble metals are known in the art.

Integrated circuits are interconnected by using well-known multilevel interconnection. The interconnect structure generally has a first metallization layer, an interconnect layer, a second metallization level, and typically third and subsequent metallization levels. Interlevel dielectric materials such as silicon dioxide and sometimes low-k materials are used to electrically isolate different metallization levels in a silicon substrate or well. The electrical connection between the different interconnect levels is achieved by using metallized vias and in particular tungsten vias. U.S. Patent No. 4,789,648 describes a method for making multiple metallized layers and metallized vias in an insulator film. In a similar manner, metal contacts are used to form electrical connections between devices and interconnect levels formed in the wells. Metal vias and contacts are typically filled with tungsten, which typically uses an adhesive layer such as titanium nitride (TiN) and / or titanium to bond a metal layer, such as a tungsten metal layer, to the dielectric material.

In one semiconductor fabrication process, the metallized vias or contacts are formed by a blanket tungsten deposition followed by a CMP step. In a typical process, a via hole is etched into an interconnect line or semiconductor substrate through an interlevel dielectric (ILD). A thin adhesion layer, such as titanium nitride and / or titanium, is then formed over the ILD and is directed to the etched via hole. A tungsten film is then blanket deposited over the adhesive layer and into the vias. The deposition continues until the via hole is filled with tungsten. Finally, excess tungsten is removed by chemical mechanical polishing (CMP) to form a metal bias.

Chemical mechanical planarization (CMP) for planarization of semiconductor substrates is well known to those skilled in the art and is described in a number of patents and publications.

In a typical CMP process, a substrate (e.g., a wafer) is placed in contact with a rotating polishing pad attached to a platen. A CMP slurry, typically an abrasive, and a chemical reaction mixture are fed to the pad during CMP processing of the substrate. During the CMP process, the wafer carrier system or polishing head applies pressure (downward force) against the substrate as the pad (secured to the platen) and the substrate are rotated. The slurry performs a planarization (polishing) process by chemical and mechanical interaction with the substrate film, which is planarized due to the rotational motion of the pad parallel to the substrate. Polishing continues in this manner until the desired film on the substrate is removed for the general purpose of polishing to effectively planarize the substrate. Typically, the metal CMP slurry contains an abrasive material suspended in an oxidizing aqueous medium, such as silica or alumina.

The ratio of the removal rate of the metal (e.g., tungsten) to the removal rate of the dielectric base is referred to as the "selectivity " of metal removal with respect to removal of the dielectric during CMP processing of the substrate comprised of metal and dielectric materials.

If a CMP slurry with high selectivity for metal removal associated with the dielectric is used, the metal layer is easily over-polished to form a depressed or "dishing" effect in the metallized area. This feature distortion is not allowed due to lithography and other constraints in semiconductor fabrication.

Another feature variation that is unsuitable in semiconductor fabrication is called "erosion ". Erosion is a topographic difference between the dielectric portion and a dense array of metal vias or trenches. In CMP, dense arrayed materials can be removed or eroded at a faster rate than surrounding dielectric portions. Thereby causing terrain differences between the dielectric portion and a dense metal (e.g., copper or tungsten) arrangement.

As industrial standards are moving toward smaller device features, there is a continuing need for tungsten CMP slurries that deliver good planarization of the nanostructures of IC chips. In particular, for 28 nm technology nodes and beyond, the slurry product must deliver an adjustable selectivity and an adjustable removal rate between the metal and the dielectric, degrading erosion and dishing while maintaining a sufficient removal rate.

In particular, there is a great need for tungsten CMP process (s) and slurry (s) that provide low dishing and plug recess effects, especially as the semiconductor industry continues to progress toward smaller feature sizes. The present invention provides a solution to this significant need.

The tungsten CMP slurry compositions described herein can be used to control surface abrasion in areas with tungsten vias, while providing tunable effective polishing at the desired polishing rate, controlled abrasive selectivity of tungsten for other materials such as dielectric materials imperfection), defects, corrosion, and a lower static etch rate that minimizes oxide erosion.

SUMMARY OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a tungsten film, which maintains or increases tungsten film removal rate, maintains adjustable and / or high selectivity for tungsten, low dicing / plug recesses for planarized substrates, It is useful for tungsten CMP.

In one embodiment,

a) nanoscale abrasive;

b) a solid catalyst of iron compound coated particles;

c) chemical additives selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;

d) an oxidizing agent; And

e) a liquid carrier

And a tungsten chemical mechanical polishing (CMP) composition having a pH of from about 2.0 to about 8.

In another aspect,

a) providing a polishing pad;

b) providing a chemical mechanical polishing composition;

c) contacting the surface of the semiconductor substrate with a polishing pad and a chemical mechanical polishing composition; And

d) polishing the surface of the semiconductor substrate

A method of chemically and mechanically polishing a tungsten-containing semiconductor substrate,

The chemical mechanical polishing composition

1) Nanoscale abrasive;

2) solid catalysts of iron compound coated particles;

3) a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;

4) oxidants; And

e) a remainder comprising a substantially liquid carrier, wherein the pH is from about 2.0 to about 8,

Wherein at least a portion of the surface containing tungsten is contacted with both the polishing pad and the chemical mechanical polishing composition.

In yet another aspect,

the method comprising: a) providing a semiconductor substrate having a surface containing tungsten and at least one other material;

b) providing a polishing pad;

c) providing a chemical mechanical polishing (CMP) composition;

d) contacting the surface of the semiconductor substrate with a polishing pad and a chemical mechanical polishing composition; And

e) polishing the surface of the semiconductor;

A method of selective chemical mechanical polishing comprising:

The chemical mechanical polishing composition comprises

1) Nanoscale abrasive;

2) solid catalysts of iron compound coated particles;

3) a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;

4) oxidants; And

5) the remainder comprising a substantially liquid carrier, wherein the pH is from about 2.0 to about 8,

At least a portion of the surface containing tungsten is contacted with both the polishing pad and the chemical mechanical polishing composition,

Wherein the ratio of the removal rate of tungsten to the removal rate of at least one other material is 1 or greater.

In yet another aspect,

a) a semiconductor substrate having a surface containing tungsten and at least one other material;

b) a polishing pad; And

c) chemical mechanical polishing (CMP) composition

A selective chemical mechanical polishing system comprising:

The chemical mechanical polishing composition comprises

1) Nanoscale abrasive;

2) solid catalysts of iron compound coated particles;

3) a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;

4) oxidants; And

5) the remainder comprising a substantially liquid carrier, wherein the pH is from about 2.0 to about 8,

Wherein at least a portion of the surface containing tungsten is contacted with both the polishing pad and the chemical mechanical polishing composition.

Optionally, the chemical mechanical polishing (CMP) composition comprises

Corrosion inhibitors;

pH buffering agents;

Surfactants; And

A biocide (when the pH of the polishing composition is 5.0 to 8.0)

≪ / RTI >

Typically, the nano-sized abrasive is selected from the group consisting of silica, alumina, ceria, titania, zirconia, and combinations thereof.

Solid catalysts are iron compound coated particles. Particles used in the preparation of solid catalysts include colloidal silica and other types of colloidal or nano-sized inorganic metal oxide particles.

Examples of piperazine derivatives include, but are not limited to, substituted mono-aminopiperazine derivatives, and substituted bis-aminopiperazine derivatives and combinations thereof.

Examples of salts of cyanates include, but are not limited to, potassium cyanate, sodium cyanate, ammonium cyanate, and tetraalkylammonium cyanate.

The tungsten slurry compositions disclosed herein primarily comprise a nanoscale abrasive, a solid catalyst on the surface of the colloidal silica particles, and a selected suitable chemical additive, a selected suitable oxidizing agent, and the remainder substantially a liquid carrier.

The chemical mechanical polishing (CMP) composition comprises

Corrosion inhibitors;

pH buffering agents;

Surfactants; And

A biocide (when the pH of the polishing composition is 5.0 to 8.0)

≪ / RTI >

The nano-sized abrasive particles used in the tungsten CMP polishing compositions disclosed herein have a narrow or wide particle size distribution, various sizes, and various shapes (the various shapes of the abrasive include spherical, cobbular, agglomerate, and other shapes) Ginny refers to colloidal silicas, colloidal silicas doped with other metal oxides within the colloidal silica lattice, such as alumina doped silica particles, colloidal aluminum oxides (including alpha, beta, and gamma-type aluminum oxides) , Colloidal and photoactive titanium dioxide, cerium oxide, colloidal cerium oxide, nano-sized diamond particles, nanosized silicon nitride particles, mono-modal, bi-modal, multi-modal colloidal abrasive particles, zirconium oxide, Polymer-based soft abrasives, surface-coated or modified abrasives, And mixtures thereof. The average particle size of the abrasive particles used in the tungsten CMP polishing composition disclosed herein is preferably in the range of 5 nm to 500 nm, more preferably in the range of 15 nm to 250 nm, and most preferably in the range of 25 nm to 150 nm to be. The average particle size can be measured, for example, by dynamic light scattering technology.

The tungsten CMP polishing composition of the present invention comprises 0.1 wt% to 25 wt% of an abrasive; Preferably 0.5% to 5% by weight of the abrasive.

Typically, the solid catalyst is an iron compound coated particle. Ferric oxide is the preferred iron compound. Particles used in the preparation of the solid catalyst include colloidal silica, and other types of colloidal or nano-sized inorganic metal oxide particles. An example of a solid catalyst is ferric oxide coated on colloidal silica. Examples of ferric oxide coated colloidal silica particles suitable for use as a solid catalyst are disclosed in U.S. Patent Nos. 7,014,669, 7,029,508, and 7,447,305.

The CMP slurry of the present invention ranges from 0.01% to 10% by weight; Preferably from 0.1% to 0.5% by weight of the solid catalyst.

There are two types of chemical additives.

The first type of selected chemical additive provides a polishing composition having a low static etch rate for tungsten film. Lowering the static etch rate not only provides better corrosion protection on the surface of the tungsten metal film, but also reduces dishing, erosion and plug recesses while polishing the tungsten or tungsten-containing substrate. By reducing the static etch rate, the chemical additive is regarded as a corrosion inhibitor for tungsten metal surface corrosion protection.

The second type of chemical additive used in the tungsten abrasive composition not only behaves as a corrosion inhibitor that reduces the static etch rate on the surface of the tungsten metal film to provide better W metal surface corrosion protection, but also increases the tungsten film removal rate. The second type of chemical additive in the tungsten abrasive compositions disclosed herein is a bifunctional chemical additive.

Also, the removal rate for dielectric film polishing is not affected while the tungsten film removal rate is increased. Thus, the selectivity of tungsten / dielectric (W / D) film polishing can be increased to provide a tungsten CMP polishing slurry with higher selectivity for W / D film polishing. A tungsten chemical mechanical polishing composition containing a second type of chemical additive can provide a better corrosion protection to the tungsten film surface and a higher selectivity to polish the W / D film to meet various demands in the semiconductor industry .

Both the first chemical additive and the second chemical additive can deliver an adjustable removal rate and an adjustable selectivity to polish the W / D film.

The first type of chemical additive selected and suitable as a corrosion inhibitor for use in the disclosed tungsten CMP slurry includes, but is not limited to, piperazine and derivatives thereof.

The general molecular structure for some piperazines and derivatives thereof is as follows:

Wherein R ₁ and R ₂ are selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, alkoxy, an organic group having at least one hydroxyl group, a substituted organic sulfonic acid (-RSO ₃ H), a substituted organic sulfonic acid salt, a keto, a substituted organic acid (-RCO ₂ H), a substituted organic acid salt (-RCOOM), the substituted organic acid ester (-RCOOR '), a substituted organic amine (-RNH _2), a substituted organic amide, And combinations thereof; Organic amine-based piperazine derivatives are important chemical-mechanical polishing compositions contemplated for use as corrosion inhibitors in the tungsten chemical-mechanical polishing compositions disclosed herein. R and R 'may be, for example, hydrocarbon side chains, and M may be, for example, sodium, ammonium, or potassium. Possible substituents include fluoro and chloro. In some preferred embodiments, R < ¹ > is an alkyl amino group, preferably a linear alkyl amino group, more preferably an organic amine group, which is a primary alkyl amino group. Examples include 2-aminoethyl and 3-aminopropyl. In such embodiments, R ² is suitably hydrogen or the same group as R ¹ .

In particular, suitable piperazines and derivatives thereof include (a) substituted organic mono-aminopiperazine derivatives having the following molecular structure and (b) substituted organic bis-aminopiperazine derivatives:

(a), a mono-substituted organic amine compound bearing a suitable organic amine functional group is bonded to the nitrogen atom at position 1 or 4 on the 6-membered ring of the piperazine.

(b), a bis-substituted organic amine compound bearing a suitable organic amine functional group is bonded to the nitrogen atom at positions 1 and 4 on the six-membered ring of the piperazine.

The organic amine functional groups in both (a) and (b) are selected from the group consisting of a primary amine group, H ₂ NR-, a secondary organic amine group, HRN-R'- or a tertiary organic amine group, RR'N- (R " ₂ ' N- < / RTI >

(a) and (b), R, R ', R' 'and R' '' are selected from the group consisting of a proton (hydrogen), an alkyl, alkoxy, an organic group having at least one hydroxyl group, a substituted organic sulfonic acid, Salts, substituted organic carboxylic acids, substituted organic carboxylic acid salts, organic carboxylic acid esters, organic amines, and combinations thereof; R, R ', R "and R"' may be the same or different. (a), R "is preferably not an organic amine group. In some preferred embodiments of formulas (a) and (b), R and R ' Preferably, each R "'in the formula (b) is hydrogen. Suitably, n = 2 or 3 such that the preferred group for the piperazine ring is 2-aminoethyl and 3-aminopropyl, (2, 3, 5, 6-position) substitution at the carbon of the piperazine ring, and the substituents are the same or different. Or other variations (e.g., oxo groups) are also contemplated.

The number of n representing the different lengths of the organic alkyl groups bridging the nitrogen atom from the piperazine ring and the nitrogen atom from the organic amine or amino group may vary from 1 to 6. n = 2 or 3 is preferable.

The organic amine functional group at the 1-position of the piperazine may be the same as the organic amine functional group at the 4-position of the piperazine, or may be different from the organic amine functional group at the 4-position of the piperazine.

Examples of the first type of chemical additive include, but are not limited to:

1- (benzyloxycarbonyl) piperazine; (R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4-Boc-Piperazine-2-carboxylic acid; 1- (diphenylmethyl) piperazine; 1,4-di-Boc-piperazine-2-carboxylic acid; 2- (Piperazine-1-carbonyl) -benzoic acid; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid (2-chloro-phenyl) -amide Piperazine-1-carboxylic acid dimethylamide; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-carboxylic acid diphenylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 1- (2-butyl) -piperazine; 2-isobutyl-piperazine; 2,3-tert-butylpiperazine; r-2-isobutyl-piperazine; s-2-isobutyl-piperazine; 2-isopropyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (4-Trifluoromethylphenyl) piperazine; 1- (cyclopropylmethyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (2-Trifluoromethylphenyl) -piperazine; 1- (6-pyridazinyl) piperazine; 2- (4-trifluoromethylphenyl) piperazine; 2-phenyl-piperazine-1-carboxylic acid benzyl ester; 1- (1-naphthylmethyl) piperazine; 1- (1-pentyl) piperazine; 1- (2-pentyl) -piperazine; 1- (3-Pentyl) -piperazine; 1- (propanoyl) -piperazine; 2-phenyl-piperazine-1-carboxylic acid tert-butyl ester; 1-Boc-piperazine; 1- (4-chlorophenyl) piperazine; 1- (2-furoyl) piperazine; 1- (2-fluorophenyl) piperazine; 1- (2-hydroxyphenyl) piperazine; 1- (2-phenylethyl) piperazine; 1- (4-fluorophenyl) piperazine; 1- (2-methylbenzyl) piperazine; 1- (4-hydroxyphenyl) piperazine; 1- (4-methylbenzyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (1-phenylethyl) piperazine; 1- (2,4-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,6-xylyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (3,4-dimethylphenyl) piperazine; 1- (3,5-dimethylphenyl) piperazine; 1- (3-fluorophenyl) piperazine; 1- (3-furoyl) piperazine; 1- (N-heptyl) piperazine; 1-pivaloyl-piperazine; 2,3-dimethyl-piperazine-1-carboxylic acid tert-butyl ester; 2- (2-chlorophenyl) piperazine; 2- (4-chlorophenyl) piperazine; n-4-cbz-piperazine-2-carboxylate methyl ester; 1- (2-pyridyl) piperazine; 1- (2-methoxyphenyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-chlorobenzhydryl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (1-adamantyl) piperazine; 1- (4-nitrophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 2- (trifluoromethyl) piperazine; 1- (3,4-dichlorophenyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2,5-difluorobenzyl) piperazine; 1- (2-ethoxyethyl) piperazine; 1- (3,4-dichlorobenzyl) piperazine; 1- (3-methoxyphenyl) piperazine; 1- (cyclohexylmethyl) piperazine; 1- (3-methylphenyl) piperazine; 1- (4-methylphenyl) piperazine; 1- (3-fluorobenzyl) piperazine; 1- (4-fluorobenzyl) piperazine; 2- (3-methoxyphenyl) piperazine; 1- (3-chlorobenzyl) piperazine; 1- (Cyclopropylcarbonyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -2-benzyl-piperazine; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; S) -2-benzyl-piperazine; (S) -2-Benzyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2,2,2-trifluoroethyl) piperazine; 1- (2,3-difluorophenyl) piperazine; 1- (2,4,6-trimethylbenzyl) piperazine; 1- (2,4-dichlorobenzyl) piperazine; 1- (2,4-difluorophenyl) piperazine; 1- (2,6-dichlorobenzyl) piperazine; 1- (2-chlorobenzyl) piperazine; 1- (2-cyclohexylethyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-fluorobenzyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-phenoxyethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3,3-dimethylbutanoyl) piperazine; 1- (3,4-dichlorobenzoyl) piperazine; 1- (3- (3,5-dichlorophenyl) piperazine; 4-difluorobenzoyl) piperazine; 1- (3,4-dimethylbenzyl) piperazine; 1- (3,5-dimethoxybenzoyl) piperazine; 1- (3,5-dimethylbenzoyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-phenylpropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-chlorobenzoyl) piperazine; 1- (4-chlorobenzyl) piperazine; 1- (4-ethoxyphenyl) piperazine; 1- (4-methoxybenzoyl) -piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-phenylbutyl) -piperazine; 1- (4-pyridylmethyl) piperazine; 1- (4- tert -butylbenzyl) piperazine; 1- (cyclohexylcarbonyl) piperazine; 1- (ethanesulfonyl) piperazine; 1- (phenylacetyl) piperazine; 1-cbz-piperazine-2-carboxylic acid; 1-hexanoyl-piperazine; 1-methylsulfonyl-piperazine; 2,3-diphenyl-piperazine; 2- (2-furyl) piperazine; 2- (2-methoxyphenyl) piperazine; 2- (2-thienyl) piperazine; 2- (3-oxo-piperazine-1-carbonyl) -benzoic acid; 2- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 2- (4-methoxyphenyl) piperazine; 2- (4-methylphenyl) piperazine; 2-benzyl-piperazine; 3- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 3-oxo-piperazine-2-carboxylic acid; 3-phenyl-piperazine-1-carboxylic acid ethyl ester; 4- (4-Boc-piperazine-1-carbonyl) phenylboronic acid pinacol ester; [5- (4-Methyl-piperazine-l-sulfonyl) -pyridin-2-yl] -hydrazine; Methylpiperazine-1-carboxylate; 1-ethyl-2-methyl-piperazine; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 1- (2-methyl-allyl) -piperazine; 2- (3-Trifluoromethyl-phenyl) -piperazine; 4-N-Boc-2-methyl-piperazine; 1- (Tetrahydro-2-furoyl) -piperazine; 1- (tetrahydro-2-furylmethyl) piperazine; (R) -l-Boc-2-ethyl-piperazine; (R) -l-Boc-3-ethyl-piperazine; (S) -l-Boc-2-ethyl-piperazine; (S) -l-Boc-3-ethyl-piperazine; 1- [1- (2-methoxyphenyl) ethyl] piperazine; 1- [1- (3-methoxyphenyl) ethyl] piperazine; 1- [1- (4-methoxyphenyl) -ethyl] -piperazine; 1- [2- (2-methylphenoxy) ethyl] piperazine; 1- (4-ethoxy-benzyl) -piperazine; 1-Boc-2,6-dimethyl-piperazine; 1-Boc-3,3-dimethyl-piperazine; 1-Boc-3,5-dimethyl-piperazine; 1-Boc-5-oxo-piperazine-2-carboxylic acid; 1-N- (tert-butoxycarbonyl) -2-ethyl-piperazine; 2- (2-fluoro-phenyl) -piperazine; 2- (3-Fluoro-phenyl) -piperazine; 2-methyl-1- (3-methylphenyl) piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-acetyl-4- (4-hydroxyphenyl) piperazine; 1- [4- (trifluoromethyl) benzyl] piperazine; 1-Boc-4- (2-formylphenyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1-Boc- (4-benzyl) piperazine; 1-Boc-4- [3- (ethoxycarbonyl) phenyl] piperazine; 1-bis (4-fluorophenyl) methylpiperazine; 1-Boc-4- (3-hydroxypropyl) piperazine; 1-Boc-4- (4-formylphenyl) piperazine; 1-Boc-4- (4-methoxycarbonylphenyl) piperazine; 1- (1,3-dioxolan-2-ylmethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (1,2,3,4-tetrahydronaphthalen-2-yl) piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1-Boc-4- (2-methoxycarbonylphenyl) piperazine; 1-Boc-4- (5-nitro-2-pyridyl) piperazine; (R) -l-Boc-2-benzyl-piperazine; (R) -l-N-Boc-2-isopropylpiperazine; (R) -l-N-Boc-4-N-Fmoc-2-piperazinecarboxylic acid; (R) -l-N-cbz-2-methyl-piperazine; (R) -4-N-trityl-2-methylpiperazine; (R) -N4-benzyl-2- (benzyloxymethyl) piperazine; (S) -l-Boc-2-hydroxymethyl-piperazine; (S) -l-Boc-2-isobutyl-piperazine; (S) -l-Boc-3-benzyl-piperazine; (S) -l-Boc-3-isopropyl-piperazine; (S) -l-N-Boc-4-N-Fmoc-Piperazine-2-carboxylic acid; (S) -4-N-trityl-2-methyl-piperazine; (S) -n4-benzyl-2- (methylthioethyl) piperazine; 1 - [(2,6-dichlorophenyl) sulfonyl] piperazine; 1 - [(2-methyl-1,3-thiazol-5-yl) methyl] piperazine; 1 - [(4,5-dimethyl-1,3-oxazol-2-yl) methyl] piperazine; 1 - [(4-cyclohexylphenyl) sulfonyl] piperazine; 1 - [(4-isobutylphenyl) sulfonyl] piperazine; 1 - [(4-methyl-1,2,5-oxadiazol-3-yl) methyl] piperazine; 1 - [(4-tert-butylphenyl) sulfonyl] piperazine; 1 - [(4-tert-butyl-2,6-dimethylphenyl) sulfonyl] piperazine; 1- [1- (Pyridin-2-yl) ethyl] piperazine; 1- [1- (Pyridin-3-yl) ethyl] piperazine; 1- [1- (thiophen-2-yl) ethyl] piperazine; 1- [2- (1-propyl) -oxyethyl] -piperazine; 1- [2- (1H-pyrrol-1-yl) ethyl] piperazine; L- [2- (2-Methoxy-phenoxy) -ethyl] -piperazine; 1- [2- (Diallylamino) -ethyl] -piperazine; 1- [2- (trifluoromethyl) pyridin-4-yl] piperazine; 1- [2- (trifluoromethyl) quinol-4-yl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] -4- (2-hydroxyethyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- [3- (difluoromethoxy) benzoyl] piperazine; 1- [3- (trifluoromethyl) pyrid-2-yl] piperazine; 1- [4- (methylsulfonyl) phenyl] piperazine; 1- [4- (trifluoromethyl) pyrimido-2-yl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-Benzhydryloxy-ethyl) -piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (2-methyl-thiazol-4-ylmethyl) -piperazine; 1- (2-N-Boc-aminoethyl) piperazine; 1- (2-pyridin-2-yl-ethyl) -piperazine; 1- (2-pyridin-4-yl-ethyl) -piperazine; 1- (2-thiophen-2-yl-ethyl) piperazine; L- (3,5-Dimethyl-isoxazol-4-ylmethyl) -piperazine; 1- (3-Methoxy-benzyl) -piperazine; 1- (3-methyl-benzoyl) -piperazine; L- (3-Methyl-pyridin-2-ylmethyl) -piperazine; 1- (3-methylpyridin-2-yl) piperazine; 1- (3-methylpyridin-4-yl) piperazine; 1- (4,6-dimethylpyrimidin-2-yl) piperazine; 1- (4-Cyano-benzyl) -piperazine; 1- (4-Ethoxy-benzenesulfonyl) -piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 1- (4-fluorobenzyl) -4- (2-hydroxyethyl) piperazine; 1- (4-Hydroxy-phenyl) -piperazine-4-carboxylic acid tert-butyl ester; N-Boc-piperidine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; (R) -1-Boc-3-methylpiperazine; 1-Boc-3-oxopiperazine; 1,4-Bis- (2-methoxy-5-methyl-benzenesulfonyl) -2-methyl-piperazine; 1 - [(1-methyl-1H-pyrazol-3-yl) carbonyl] piperazine; 1 - [(1-methyl-1H-pyrazol-4-yl) methyl] piperazine; 1- (2- (N, N-bis- (2-hydroxypropyl) -amino) -ethyl) -4- (2-hydroxypropyl) -piperazine; 1- (2-methoxyphenyl) -4 - ((4- (2-methoxyphenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (3- (2,3-dihydro-1,4-benzodioxin-6-yl) acryloyl) -4- (4-fluorophenyl) piperazine; Sulfonyl} -9H-fluoren-2-yl) sulfonyl] piperazine < / RTI >; 1- (4-Fluorophenyl) -4 - ((4- (4-fluorophenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (4-Nitrophenyl) -4- (3 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; 1- (4-Nitrophenyl) -4- (4 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; L-acetyl-4- (l-ethyl-lH-imidazol-2-yl) piperazine; Yl} ethyl) -1H-pyrazol-3-yl] -1H-pyrazolo [3,4-d] Piperazine; L-benzyl-4- [2 - [(2 ', 4'-difluoro [1,1'-biphenyl] -4-yl) oxy] ethyl] piperazine; 1-Benzyl-4- (3 - ((2 ', 4'-difluoro (1,1'-biphenyl) -4-yl) oxy) propyl) piperazine; L-isopropyl-4 - [(l-methyl-lH-pyrrol-2-yl) methyl] piperazine; 1 -Methyl-4 - ({7 - [(4-methyl-1-piperazinyl) sulfonyl] -9H-fluoren-2-yl} sulfonyl) piperazine; 1-phenyl-4- [phenyl (4-phenyl-1-piperazinyl) methyl] piperazine; 1-methyl-4- (methylsulfonyl) piperazine; 4- (2-Hydroxy-ethyl) -piperazine-l-carboxylic acid (4-isopropyl-phenyl) -amide; 6-hydroxymethyl-l, 3-dimethyl-piperazine-2,5-dione; Bis (2-methoxyphenyl) 2,2 '- (piperazine-1,4-diyl) diethanesulfonate; 1- (adamantane-1-sulfinyl) -4-methyl-piperazine; 1- (phenylsulfonyl) -4- (2-pyridinyl) piperazine; 1-benzyl-4- (2-methoxypropanoyl) piperazine; 1-cyclohexyl-4- (methylsulfonyl) piperazine; 1-ethyl-4- (3-furylmethyl) piperazine; 1- (3-phenoxy-4-pyridinyl) piperazine; 1- (2-pyridinyl) -4- (3- (2,3,4-trimethoxyphenyl) acryloyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (2-pyridinyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (4-methoxyphenyl) piperazine; 1,4-bis- (2-pyridylmethyleneamino) -piperazine; (1,4-di (2-furoyl) piperazin-1-yl) piperazine, 1,4-bis- (3,4,5-trimethoxybenzylideneamino- Bis (2- (2-pyridinyl) ethyl) piperazine, 1,4-bis [2- (4-pyridinyl) ethyl] piperazine, (3-pyridinylmethyl) piperazine, 1- (ethoxycarbonylmethyl) piperazine, 2,3,5,6-tetrahydroxy-piperazine-1,4-dicar Diethyl 2,2 '- (piperazine-1,4-diyl) bis (2-oxoacetate); diethyl 2,2' - (2E, 2'E) -3,3 '- (piperazine-1,4-diyl) diacetate; dimethyl 3,3' (2-hydroxyphenyl) prop-2-en-1-one); 2,2 '- (piperazine-1,4-diyl) bis 2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) acetamide); 2,2 '- (piperazine- (Piperazine-1,4-diyl) bis (1- (9H-carbazol-9-yl) Propane-2-ol) fumarate, 3,3 '- (piperazine-1,4-diyl) bis (1-phenylpropan- 4,4'- (piperazine-1,4-diyl) bis (3-ethoxycyclobut-3-en-1,2-dione; piperazine- Di-tert-butyl-piperazine-2,5-dione, 1,4-didodecyl-piperazine, 1,4-dihexadecyl-piperazine, 1- 1- (3-pyridinylcarbonyl) piperazine, 1- (3-pyridinylcarbonyl) piperazine, 1- (R) -3-methyl-2-ketopiperazine; 4- (Boc-piperazin-l- (Piperazin-1, 4-diyl) bis (1-phenyl-1,4-diyl) Ethanol); 2,2 '- (piperazine-1,4-diyl) bis (2- Ropan nitrile); Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; Citric acid sesquipiperazine salt hydrate; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; Escropipate; 1-piperazine propanol; t-butyl-4- (2-amino-1-phenylethyl) piperazine carboxylate; Tert-butyl 4- [2- (aminomethyl) phenyl] piperazine-1-carboxylate; Tert-butyl 4- [5- (hydroxymethyl) pyrid-2-yl] piperazine-1-carboxylate; Tert-butyl 4- (3-aminobenzyl) piperazine-1-carboxylate; Tert-butyl 4- (4 - [(methylamino) methyl] phenyl) piperazine-1-carboxylate; Tert-butyl 4- (4-cyanopyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (5-formylpyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (oxetan-3-yl) piperazine-1-carboxylate; Tert-Butyl 4- (piperidin-3-yl) piperazine-1-carboxylate; Tert-butyl 4- (pyrrolidin-2-ylcarbonyl) piperazine-1-carboxylate; Tert-Butyl 4- (lH-pyrrolo [2,3-b] pyridin-4-yl) piperazine-1-carboxylate; 1- [2- (2,5-dimethyl-1H-pyrrol-1-yl) ethyl] piperazine; 1 - ((1,5-dimethyl-1H-pyrazol-4-yl) methyl) piperazine; L- (l-Ethyl-5-methyl-lH-pyrazol-4-ylmethyl) -piperazine; t-butyl 4- (2-amino-1- [4- (trifluoromethyl) phenyl] ethyl) piperazinecarboxylate; 3- (4-Fluoro-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3- (4-Hydroxy-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3-furan-2-yl-piperazine-1-carboxylic acid tert-butyl ester; 3-thiophen-2-yl-piperazine-1-carboxylic acid benzyl ester; 4- (2-Amino-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 4- (2-aminoethyl) -1-boc-piperazine; 4- (5-Carboxy-pyridin-2-yl) -2-methyl-piperazine-1-carboxylic acid tert-butyl ester; 4-Boc-l- (6-methyl-2-pyridyl) piperazine; Fmoc-4-carboxymethyl-piperazine; Methyl 4-Boc-piperazine-2-carboxylate; N, N-dimethyl-1-piperazinesulfonamide; N-1-Boc-N-4-Fmoc-2-piperazinecarboxylic acid; N-4-Boc-N-1-cbz-2-piperazinecarboxylic acid; N-4-Boc-N-1-Fmoc-2-piperazineacetic acid; A sulfuric acid compound having piperazine-1-carboximidamide (1: 1); 1-ethyl-4-piperidin-4-yl-piperazine; 1-furan-2-ylmethyl-piperazine; L-Methyl-4- (2-piperidin-4-yl-ethyl) -piperazine; 1-Methyl-4- (6-aminopyridin-3-yl) piperazine; 1-Methyl-4- (piperidin-4-yl) -piperazine; 1-N-Boc-4- (Azetidin-3-yl) piperazine; 1-pyridin-2-ylmethyl-piperazine; 1-pyridin-3-ylmethyl-piperazine; 1 -thiazol-2-yl-piperazine; 2- (2,5-dimethoxy-phenyl) -piperazine; 2-carboxymethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; 2-ethoxycarbonylmethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; L- (4-Methyl-cyclohexyl) -piperazine; L- (4-Methyl-piperidine-l-sulfonyl) -piperazine; L- (4-Trifluoromethyl-pyridin-2-yl) -piperazine; 1- (5-methyl-2-pyridinyl) piperazine; 1- (5-methyl-2-thiazolyl) -piperazine; 1- (5-nitropyridin-2-yl) piperazine; 1- (6-butoxy-2-pyridinyl) piperazine; 1- (6-methylpyrid-2-yl) piperazine; 1- (N-methylpiperidin-3-yl-methyl) piperazine; 1- (thien-2-ylacetyl) piperazine; 1-Boc-4- (piperidin-4-yl) -piperazine; 1-Boc-4-cyanomethylpiperazine; 1-cyclohex-3-enylmethyl-piperazine. The piperazine derivatives are preferably (R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 2-isobutyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (6-pyridazinyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (2-pyridyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2-ethoxyethyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-pyridylmethyl) -piperazine; 1- (ethanesulfonyl) piperazine; 3-oxo-piperazine-2-carboxylic acid; 4-methylpiperazine-1-carboxylate; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; 1,4-bis (3-pyridinylmethyl) piperazine; 1- (ethoxycarbonylmethyl) piperazine; 2,3,5,6-Tetrahydroxy-piperazine-1,4-dicarbaldehyde; Dimethyl 3,3 '- (piperazine-1,4-diyl) dipropanoate; 2,2 '-( piperazine-1,4-diyl) < / RTI > 2,2 '- (piperazine-1,4-diyl) dipropanenitrile; (R) -3-methyl-2-ketopiperazine; 2,2 '- (Piperazine-1,4-diyl) bis (2-methylpropanenitrile); Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; And combinations thereof. Optionally, where the (R) or (S) enantiomer of the active compound is specified, the opposite enantiomer, and racemates or other mixtures of the enantiomers are also contemplated.

Two examples of such first type of chemical additives as corrosion inhibitors for the disclosed tungsten CMP polishing compositions are as follows: mono-substituted 1- (2-aminoethyl) piperazine (in case of (a)) and bis- Substituted 1,4-bis (3-aminopropyl) piperazine (in case of (b)).

The CMP slurry of the present invention has a range of 0.0001% to 0.10%; Preferably from 0.0005% to 0.010%, of the first type of chemical additive.

A second type of chemical additive with dual functionality that provides corrosion protection to the surface of tungsten metal film as a corrosion inhibitor and increases tungsten film removal rate as a tungsten removal rate booster includes various salts of cyanate (CNO) do. Such cyanate salts include alkylammonium cyanates including potassium cyanate, sodium cyanate, ammonium cyanate, and tetraalkylammonium cyanate.

The CMP slurry of the present invention has a range of 0.0002% to 0.5%; Preferably from 0.001% to 0.25%, of the second type of chemical additive.

The oxidizing agent used in the disclosed tungsten CMP slurry includes periodic acid, hydrogen peroxide, potassium iodate, potassium permanganate, ammonium persulfate, ammonium molybdate, ferric nitrate, nitric acid, potassium nitrate, and mixtures thereof , But is not limited thereto. A preferred oxidizing agent is hydrogen peroxide.

The CMP slurry of the present invention comprises 0.5 wt% to 10 wt%; Preferably 1% to 4% by weight; Most preferably from 2% to 3% by weight of the oxidizing agent.

The liquid carrier providing the major part of the liquid component may be water or a mixture of water and other liquids which are miscible with water. Advantageously, the solvent is water, such as DI (deionized) water.

The pH buffering agents used in the disclosed tungsten CMP slurries include, but are not limited to, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, other inorganic or organic acids, and compounds thereof. A preferred pH controlling agent is nitric acid.

The CMP slurry of the present invention comprises 0.01% to 0.5% by weight; Preferably from 0.05% to 0.15% by weight of nitric acid.

Corrosion inhibitors for use in the disclosed tungsten CMP slurries include, but are not limited to, polyethyleneimine, and other organic polymers or oligomeric primary and secondary amines.

The CMP slurry of the present invention ranges from 0.0001 wt% to 0.25 wt%; Preferably from 0.0003% to 0.01% by weight, based on the total weight of the composition.

Surfactants used in the disclosed tungsten CMP slurries include, but are not limited to,

(a) nonionic surface wetting agent

Nonionic surface wetting agents are typically oxygen- or nitrogen-containing compounds having various hydrophobic and hydrophilic moieties in the same molecule, with molecular weights ranging from a few hundred to over a million. The viscosity of these materials is also very broad.

(b) anionic surface wetting agent

Such compounds have a negative net charge on a major portion of the molecular skeleton and such compounds can be prepared by reacting the following salts with suitable hydrophobic tailings such as alkyl carboxylates, alkyl sulphates, alkyl phosphates, alkyl sulphonates, alkyl sulphates, alkyl sulphates, Substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, substituted arylsulfates, Substituted arylsulfates, substituted arylsulfates, and the like, but are not limited thereto. Counter-ions for this type of surface wetting agent include, but are not limited to, the following ions, e.g., potassium, ammonium, and other cations. The molecular weight of such anionic surface wetting agents ranges from hundreds to hundreds of thousands.

(c). Cationic surface wetting agent

Such compounds have a positive net charge on a major portion of the molecular backbone and such compounds include the following salts with suitable hydrophilic tail, such as carboxylate, sulfate, phosphate, bicarboxylate, bisulfate, biphosphate, But is not limited thereto. Counter-ions for this type of surface wetting agent include, but are not limited to, the following ions, e.g., potassium, ammonium, and other cations. The molecular weight of such anionic surface wetting agents ranges from hundreds to hundreds of thousands.

(d). Amphoteric surface wetting agent

These compounds have both positive and negative charges on the main molecular chain and with their associated counter ions. Examples of such bipolar surface wetting agents include, but are not limited to, amino-carboxylic acids, amino-phosphoric acids, and salts of amino-sulfonic acids.

The surfactant used in the tungsten CMP slurry ranges from 0.0001% to 0.50%; And preferably in the range of 0.0005% to 0.10%.

The biocides used in the disclosed tungsten CMP slurries include, but are not limited to, commercially available biocidal products such as Kathon, Kathon II, and the like.

The biocide used in the tungsten CMP slurry ranges from 0.0001% to 0.1%; And preferably in the range of 0.0005% to 0.010%.

The present invention is further demonstrated by the following examples.

Example of work

The related processes described herein involve the use of the above-mentioned compositions for the chemical mechanical planarization of substrates comprising tungsten.

In such a process, a substrate (e.g., a wafer having a W surface) is placed face-down toward a polishing pad that is fixedly attached to a rotatable platen of a CMP polisher. In this way, the substrate to be polished and planarized is placed in direct contact with the polishing pad. The wafer carrier system or polishing head is used to hold the substrate in place during the rotation of the platen and substrate and apply a downward pressure against the backside of the substrate during CMP processing. The polishing composition (slurry) is applied (usually continuously) on the pad during the CMP process to cause removal of the material to planarize the substrate.

The polishing compositions and related processes described herein are effective for CMP of a wide variety of substrates, including most substrates they carry, and are particularly useful for polishing tungsten substrates.

Overall experiment course

In the examples presented below, CMP experiments were performed using the following process and experimental conditions.

The CMP equipment used in the examples is Mirra < ( ^R) > manufactured by Applied Materials (3050 Bowers Avenue, Santa Clara, California, 95054). For blanket wafer polishing studies, IC-1010 pads supplied by Dow Chemicals on platens were used. The pad was broken-in by polishing a 25 dummy oxide (deposited by plasma enhanced CVD from a TEOS precursor, PETEOS) wafer.

Machine settings and the pad break-in in order to verify the person, were polished with two PETEOS monitors under baseline conditions with Syton ^® OX-K colloidal silica supplied by Air Products Chemicals leveling platform (Platform Planarization) Inc. of. The polishing experiments were carried out using 8K angstrom thick blanket W wafers, and TEOS wafers. These blanket wafers were purchased from Silicon Valley Microelectronics (1150 Campbell Ave, CA, 95126).

parameter

Å: Angstrom - length unit

W: Tungsten

BP: back pressure, psi unit

CMP: chemical mechanical planarization = chemical mechanical polishing

CS: Carrier speed

DF: Downward force: Pressure applied during CMP, in psi

min: min (s)

ml: Milliliter (s)

mV: millivolts (s)

psi: pounds per square inch

PS: Platen rotational speed, rpm (revolutions per minute) of the abrasive machine

SF: polishing composition flow, ml / min

Weight percent: Weight percent (of listed ingredients)

TEOS: tetraethyl orthosilicate

NU% (or WIWNU%): With-In Wafer Non-Uniformity%

NU% = (| W film thickness before polishing - W film thickness after W polishing | / average of total W film thickness) X 100%

W RR 3.0 psi: Tungsten removal rate measured at 3.0 psi downstream pressure of CMP equipment

TEOS RR 3.0 psi: TEOS removal rate measured at 3.0 psi downstream pressure of CMP equipment

W: TEOS selectivity: (W removal rate) / (TEOS removal rate) at the same downward force (3.0 psi)

Static etching rate

The static etch rate is a measure providing experimental data relating to the chemical activity level of the CMP slurry. Typically, a higher static etch rate is indicative of a more aggressive chemical composition that results in a relatively rapid etch of the associated metal film surface, which is more likely to cause more metal corrosion defects.

A chip cut from a tungsten blanket wafer was exposed to both a standard tungsten slurry and the disclosed CMP tungsten polishing formulation.

The standard W slurry shown in Table 1 includes:

0.4 wt% solid catalyst-ferric oxide coated on colloidal silica;

0.5% by weight of colloidal silica;

3.0 wt% hydrogen peroxide; And

DI to the rest.

The pH at the point of use is about 3.4.

Table 1 shows normalized data of the static etch rate collected at a temperature of 40 DEG C for 5 minutes.

Addition of a selected chemical additive that acts as a corrosion inhibitor at a temperature of 40 DEG C in a standard W slurry can result in a static etch rate of up to 90% in the case of 1 (2-aminoethyl) piperazine as the additive, and of potassium cyanate , And to 74% in the case of 1,4-diazabicyclo [2.2.2] octane (comparative) as an additive.

In the tests shown in Table 1, standard W slurries contained 0.00025% for 1 (2-aminoethyl) piperazine, 0.001% for potassium cyanate, and 1, 2-diazabicyclo [2.2.2 ] Octane, 0.010% was added.

The data in Table 1 indicate excellent corrosion protection at the temperature reached (40 DEG C) due to friction during polishing.

Table 1. Effect of Corrosion Inhibitor on Static Etch Rate of Tungsten Metal

Chemical mechanical polishing

Chemical mechanical polishing was performed using the first type of chemical additive as a corrosion inhibitor and the second type of chemical additive as a dual functional additive to provide corrosion protection to the tungsten metal film surface and to increase the tungsten film removal rate.

Test results are listed in Tables 2 and 3 for the first and second chemical additives, respectively.

In Table 2, 10 ppm of 1- (2-aminoethyl) piperazine was defined as 1X of 1- (2-aminoethyl) piperazine added during the standard W slurry formulation.

The standard W slurry shown in Table 2

0.4 wt% solid catalyst-ferric oxide coated on colloidal silica;

0.5% by weight of colloidal silica;

3.0 wt% hydrogen peroxide; And

The remainder includes the DI number.

The pH at the point of use is about 3.4.

Table 2. Effect of first chemical additive on W CMP slurry performance

As shown in Table 2, the addition of the first type of chemical additive, especially 1- (2-aminoethyl) piperazine, in the standard W CMP slurry reduces the NU%.

Since the 1- (2-aminoethyl) piperazine behaved as a strong corrosion inhibitor for the W CMP slurry formulation, the tungsten removal rate decreased as the concentration of 1- (2-aminoethyl) piperazine was increased.

Table 2 also shows the adjustable selectivity of W: TEOS with varying concentrations of 1- (2-aminoethyl) piperazine.

In Table 3, 25 ppm of potassium cyanate was defined as 1X potassium cyanate used in the sample slurry.

In Table 3, the 1X KCNO slurry

0.4 wt% solid catalyst-ferric oxide coated on colloidal silica;

0.5% by weight of colloidal silica;

3.0 wt% hydrogen peroxide;

25 ppm potassium cyanate; And

The remainder includes the DI number.

The pH at the point of use is about 3.4.

The reference W slurry shown in Table 3

0.4 wt% solid catalyst-ferric oxide coated on colloidal silica;

0.5% by weight of colloidal silica;

3.0 wt% hydrogen peroxide;

0.00037% by weight of polyethyleneimine; And

The remainder includes the DI number.

The pH at the point of use is about 3.4.

Table 3. Effect of second type of chemical additive on W CMP slurry performance

As shown in Table 3, various excellent results were observed by adding a second type of chemical additive, potassium cyanate, to the standard tungsten CMP slurry.

The removal rate of tungsten film increased to over 25% when potassium cyanate in the concentration of 1X, 2X, or 4X was added in a standard tungsten chemical mechanical polishing composition.

When using 1X, 2X, or 4X potassium cyanate as an additive, the NU% decreased from 6.29% to 3.07%, 2.93%, and 2.87%, respectively.

The selectivity of W / D film polishing increased from 141 to 336, 332, and 272, respectively, when using 1X, 2X, or 4X potassium cyanate as an additive.

The use of potassium cyanate provided a high selectivity as well as an adjustable selectivity of W: TEOS while decreasing NU%.

In contrast to the standard W slurry, an increase in W film removal rate of 20% or more was still observed with NU% at 4.02% even at a concentration of 2 ppm of potassium cyanate (0.08X POU concentration).

Embodiments of the invention enumerated above, including working examples, are illustrative of a number of embodiments that may be made of the present invention. It should be appreciated that a number of different configurations of processes may be utilized and that the materials used in the process may be selected from a number of materials rather than the materials explicitly disclosed.

Claims (24)

a) from 0.1% to 25% by weight of nano-sized abrasive selected from the group consisting of silica, alumina, ceria, titania, zirconia, and combinations thereof;
b) from 0.1% to 0.5% by weight of iron compound coated particles selected from the group consisting of iron compound coated colloidal silica, iron compound-coated colloidal or nano sized inorganic metal oxide particles, and combinations thereof Solid catalyst;
c) 0.0001% to 0.5% by weight of a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;
d) 0.5% to 10% by weight of an oxidizing agent; And
e) a tungsten chemical mechanical polishing (CMP) composition comprising a liquid carrier and having a pH of from about 2.0 to about 8.0. The tungsten chemical mechanical polishing (CMP) composition of claim 1, wherein the chemical additive is a piperazine derivative having the following general molecular formula:

Wherein R ₁ and R ₂ are selected from the group consisting of hydrogen, aryl, aralkyl, alkyl, alkoxy, an organic group having at least one hydroxyl group, a substituted organic sulfonic acid, a substituted organic sulfonic acid salt, a substituted organic carboxylic acid, An organic carboxylic acid salt, an organic carboxylic acid salt, a substituted organic carboxylic acid amide, a substituted keto, an organic carboxylic acid ester, an organic amine, and combinations thereof. The tungsten chemical mechanical polishing (CMP) composition of claim 1, wherein the piperazine derivative is a substituted organic mono-aminopiperazine derivative (a) or a substituted organic bis-aminopiperazine derivative (b) :

In this formula,
n is independently selected from 1 to 6;
R, R ', R "and R"' are independently selected from the group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, organic groups having at least one hydroxyl group, substituted organic sulfonic acids, substituted organic sulfonic acid salts, , Substituted organic carboxylic acid salts, substituted keto, organic carboxylic acid esters, organic amines, substituted organic carboxylic acid amides, and combinations thereof. 2. A compound according to claim 1, wherein the piperazine derivative is
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4-Boc-Piperazine-2-carboxylic acid; 1- (diphenylmethyl) piperazine; 1,4-di-Boc-piperazine-2-carboxylic acid; 2- (Piperazine-1-carbonyl) -benzoic acid; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid; (2-chloro-phenyl) -amide Piperazine-1-carboxylic acid dimethylamide; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-carboxylic acid diphenylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 1- (2-butyl) -piperazine; 2-isobutyl-piperazine; 2,3-tert-butylpiperazine; r-2-isobutyl-piperazine; s-2-isobutyl-piperazine; 2-isopropyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (4-Trifluoromethylphenyl) piperazine; 1- (cyclopropylmethyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (2-Trifluoromethylphenyl) -piperazine; 1- (6-pyridazinyl) piperazine; 2- (4-trifluoromethylphenyl) piperazine; 2-phenyl-piperazine-1-carboxylic acid benzyl ester; 1- (1-naphthylmethyl) piperazine; 1- (1-pentyl) piperazine; 1- (2-pentyl) -piperazine; 1- (3-Pentyl) -piperazine; 1- (propanoyl) -piperazine; 2-phenyl-piperazine-1-carboxylic acid tert-butyl ester; 1-Boc-piperazine; 1- (4-chlorophenyl) piperazine; 1- (2-furoyl) piperazine; 1- (2-fluorophenyl) piperazine; 1- (2-hydroxyphenyl) piperazine; 1- (2-phenylethyl) piperazine; 1- (4-fluorophenyl) piperazine; 1- (2-methylbenzyl) piperazine; 1- (4-hydroxyphenyl) piperazine; 1- (4-methylbenzyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (1-phenylethyl) piperazine; 1- (2,4-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,6-xylyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (3,4-dimethylphenyl) piperazine; 1- (3,5-dimethylphenyl) piperazine; 1- (3-fluorophenyl) piperazine; 1- (3-furoyl) piperazine; 1- (N-heptyl) piperazine; 1-pivaloyl-piperazine; 2,3-dimethyl-piperazine-1-carboxylic acid tert-butyl ester; 2- (2-chlorophenyl) piperazine; 2- (4-chlorophenyl) piperazine; n-4-cbz-piperazine-2-carboxylate methyl ester; 1- (2-pyridyl) piperazine; 1- (2-methoxyphenyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-chlorobenzhydryl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (1-adamantyl) piperazine; 1- (4-nitrophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 2- (trifluoromethyl) piperazine; 1- (3,4-dichlorophenyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2,5-difluorobenzyl) piperazine; 1- (2-ethoxyethyl) piperazine; 1- (3,4-dichlorobenzyl) piperazine; 1- (3-methoxyphenyl) piperazine; 1- (cyclohexylmethyl) piperazine; 1- (3-methylphenyl) piperazine; 1- (4-methylphenyl) piperazine; 1- (3-fluorobenzyl) piperazine; 1- (4-fluorobenzyl) piperazine; 2- (3-methoxyphenyl) piperazine; 1- (3-chlorobenzyl) piperazine; 1- (Cyclopropylcarbonyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -2-benzyl-piperazine; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; S) -2-benzyl-piperazine; (S) -2-Benzyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2,2,2-trifluoroethyl) piperazine; 1- (2,3-difluorophenyl) piperazine; 1- (2,4,6-trimethylbenzyl) piperazine; 1- (2,4-dichlorobenzyl) piperazine; 1- (2,4-difluorophenyl) piperazine; 1- (2,6-dichlorobenzyl) piperazine; 1- (2-chlorobenzyl) piperazine; 1- (2-cyclohexylethyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-fluorobenzyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-phenoxyethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3,3-dimethylbutanoyl) piperazine; 1- (3,4-dichlorobenzoyl) piperazine; 1- (3- (3,5-dichlorophenyl) piperazine; 4-difluorobenzoyl) piperazine; 1- (3,4-dimethylbenzyl) piperazine; 1- (3,5-dimethoxybenzoyl) piperazine; 1- (3,5-dimethylbenzoyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-phenylpropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-chlorobenzoyl) piperazine; 1- (4-chlorobenzyl) piperazine; 1- (4-ethoxyphenyl) piperazine; 1- (4-methoxybenzoyl) -piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-phenylbutyl) -piperazine; 1- (4-pyridylmethyl) piperazine; 1- (4- tert -butylbenzyl) piperazine; 1- (cyclohexylcarbonyl) piperazine; 1- (ethanesulfonyl) piperazine; 1- (phenylacetyl) piperazine; 1-cbz-piperazine-2-carboxylic acid; 1-hexanoyl-piperazine; 1-methylsulfonyl-piperazine; 2,3-diphenyl-piperazine; 2- (2-furyl) piperazine; 2- (2-methoxyphenyl) piperazine; 2- (2-thienyl) piperazine; 2- (3-oxo-piperazine-1-carbonyl) -benzoic acid; 2- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 2- (4-methoxyphenyl) piperazine; 2- (4-methylphenyl) piperazine; 2-benzyl-piperazine; 3- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 3-oxo-piperazine-2-carboxylic acid; 3-phenyl-piperazine-1-carboxylic acid ethyl ester; 4- (4-Boc-piperazine-1-carbonyl) phenylboronic acid pinacol ester; [5- (4-Methyl-piperazine-l-sulfonyl) -pyridin-2-yl] -hydrazine; Methylpiperazine-1-carboxylate; 1-ethyl-2-methyl-piperazine; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 1- (2-methyl-allyl) -piperazine; 2- (3-Trifluoromethyl-phenyl) -piperazine; 4-N-Boc-2-methyl-piperazine; 1- (Tetrahydro-2-furoyl) -piperazine; 1- (tetrahydro-2-furylmethyl) piperazine; (R) -l-Boc-2-ethyl-piperazine; (R) -l-Boc-3-ethyl-piperazine; (S) -l-Boc-2-ethyl-piperazine; (S) -l-Boc-3-ethyl-piperazine; 1- [1- (2-methoxyphenyl) ethyl] piperazine; 1- [1- (3-methoxyphenyl) ethyl] piperazine; 1- [1- (4-methoxyphenyl) -ethyl] -piperazine; 1- [2- (2-methylphenoxy) ethyl] piperazine; 1- (4-ethoxy-benzyl) -piperazine; 1-Boc-2,6-dimethyl-piperazine; 1-Boc-3,3-dimethyl-piperazine; 1-Boc-3,5-dimethyl-piperazine; 1-Boc-5-oxo-piperazine-2-carboxylic acid; 1-N- (tert-butoxycarbonyl) -2-ethyl-piperazine; 2- (2-fluoro-phenyl) -piperazine; 2- (3-Fluoro-phenyl) -piperazine; 2-methyl-1- (3-methylphenyl) piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-acetyl-4- (4-hydroxyphenyl) piperazine; 1- [4- (trifluoromethyl) benzyl] piperazine; 1-Boc-4- (2-formylphenyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1-Boc- (4-benzyl) piperazine; 1-Boc-4- [3- (ethoxycarbonyl) phenyl] piperazine; 1-bis (4-fluorophenyl) methylpiperazine; 1-Boc-4- (3-hydroxypropyl) piperazine; 1-Boc-4- (4-formylphenyl) piperazine; 1-Boc-4- (4-methoxycarbonylphenyl) piperazine; 1- (1,3-dioxolan-2-ylmethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (1,2,3,4-tetrahydronaphthalen-2-yl) piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1-Boc-4- (2-methoxycarbonylphenyl) piperazine; 1-Boc-4- (5-nitro-2-pyridyl) piperazine; (R) -l-Boc-2-benzyl-piperazine; (R) -l-N-Boc-2-isopropylpiperazine; (R) -l-N-Boc-4-N-Fmoc-2-piperazinecarboxylic acid; (R) -l-N-cbz-2-methyl-piperazine; (R) -4-N-trityl-2-methylpiperazine; (R) -N4-benzyl-2- (benzyloxymethyl) piperazine; (S) -l-Boc-2-hydroxymethyl-piperazine; (S) -l-Boc-2-isobutyl-piperazine; (S) -l-Boc-3-benzyl-piperazine; (S) -l-Boc-3-isopropyl-piperazine; (S) -l-N-Boc-4-N-Fmoc-Piperazine-2-carboxylic acid; (S) -4-N-trityl-2-methyl-piperazine; (S) -n4-benzyl-2- (methylthioethyl) piperazine; 1 - [(2,6-dichlorophenyl) sulfonyl] piperazine; 1 - [(2-methyl-1,3-thiazol-5-yl) methyl] piperazine; 1 - [(4,5-dimethyl-1,3-oxazol-2-yl) methyl] piperazine; 1 - [(4-cyclohexylphenyl) sulfonyl] piperazine; 1 - [(4-isobutylphenyl) sulfonyl] piperazine; 1 - [(4-methyl-1,2,5-oxadiazol-3-yl) methyl] piperazine; 1 - [(4-tert-butylphenyl) sulfonyl] piperazine; 1 - [(4-tert-butyl-2,6-dimethylphenyl) sulfonyl] piperazine; 1- [1- (Pyridin-2-yl) ethyl] piperazine; 1- [1- (Pyridin-3-yl) ethyl] piperazine; 1- [1- (thiophen-2-yl) ethyl] piperazine; 1- [2- (1-propyl) -oxyethyl] -piperazine; 1- [2- (1H-pyrrol-1-yl) ethyl] piperazine; L- [2- (2-Methoxy-phenoxy) -ethyl] -piperazine; 1- [2- (Diallylamino) -ethyl] -piperazine; 1- [2- (trifluoromethyl) pyridin-4-yl] piperazine; 1- [2- (trifluoromethyl) quinol-4-yl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] -4- (2-hydroxyethyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- [3- (difluoromethoxy) benzoyl] piperazine; 1- [3- (trifluoromethyl) pyrid-2-yl] piperazine; 1- [4- (methylsulfonyl) phenyl] piperazine; 1- [4- (trifluoromethyl) pyrimido-2-yl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-Benzhydryloxy-ethyl) -piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (2-methyl-thiazol-4-ylmethyl) -piperazine; 1- (2-N-Boc-aminoethyl) piperazine; 1- (2-pyridin-2-yl-ethyl) -piperazine; 1- (2-pyridin-4-yl-ethyl) -piperazine; 1- (2-thiophen-2-yl-ethyl) piperazine; L- (3,5-Dimethyl-isoxazol-4-ylmethyl) -piperazine; 1- (3-Methoxy-benzyl) -piperazine; 1- (3-methyl-benzoyl) -piperazine; L- (3-Methyl-pyridin-2-ylmethyl) -piperazine; 1- (3-methylpyridin-2-yl) piperazine; 1- (3-methylpyridin-4-yl) piperazine; 1- (4,6-dimethylpyrimidin-2-yl) piperazine; 1- (4-Cyano-benzyl) -piperazine; 1- (4-Ethoxy-benzenesulfonyl) -piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 1- (4-fluorobenzyl) -4- (2-hydroxyethyl) piperazine; 1- (4-Hydroxy-phenyl) -piperazine-4-carboxylic acid tert-butyl ester; (Currently 14 pages) N-Boc-piperidine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; (R) -1-Boc-3-methylpiperazine; 1-Boc-3-oxopiperazine; 1,4-Bis- (2-methoxy-5-methyl-benzenesulfonyl) -2-methyl-piperazine; 1 - [(1-methyl-1H-pyrazol-3-yl) carbonyl] piperazine; 1 - [(1-methyl-1H-pyrazol-4-yl) methyl] piperazine; 1- (2- (N, N-bis- (2-hydroxypropyl) -amino) -ethyl) -4- (2-hydroxypropyl) -piperazine; 1- (2-methoxyphenyl) -4 - ((4- (2-methoxyphenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (3- (2,3-dihydro-1,4-benzodioxin-6-yl) acryloyl) -4- (4-fluorophenyl) piperazine; Sulfonyl} -9H-fluoren-2-yl) sulfonyl] piperazine < / RTI >; 1- (4-Fluorophenyl) -4 - ((4- (4-fluorophenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (4-Nitrophenyl) -4- (3 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; 1- (4-Nitrophenyl) -4- (4 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; L-acetyl-4- (l-ethyl-lH-imidazol-2-yl) piperazine; Yl} ethyl) -1H-pyrazol-3-yl] -1H-pyrazolo [3,4-d] Piperazine; L-benzyl-4- [2 - [(2 ', 4'-difluoro [1,1'-biphenyl] -4-yl) oxy] ethyl] piperazine; 1-Benzyl-4- (3 - ((2 ', 4'-difluoro (1,1'-biphenyl) -4-yl) oxy) propyl) piperazine; L-isopropyl-4 - [(l-methyl-lH-pyrrol-2-yl) methyl] piperazine; 1 -Methyl-4 - ({7 - [(4-methyl-1-piperazinyl) sulfonyl] -9H-fluoren-2-yl} sulfonyl) piperazine; 1-phenyl-4- [phenyl (4-phenyl-1-piperazinyl) methyl] piperazine; 1-methyl-4- (methylsulfonyl) piperazine; 4- (2-Hydroxy-ethyl) -piperazine-l-carboxylic acid (4-isopropyl-phenyl) -amide; 6-hydroxymethyl-l, 3-dimethyl-piperazine-2,5-dione; Bis (2-methoxyphenyl) 2,2 '- (piperazine-1,4-diyl) diethanesulfonate; 1- (adamantane-1-sulfinyl) -4-methyl-piperazine; 1- (phenylsulfonyl) -4- (2-pyridinyl) piperazine; 1-benzyl-4- (2-methoxypropanoyl) piperazine; 1-cyclohexyl-4- (methylsulfonyl) piperazine; 1-ethyl-4- (3-furylmethyl) piperazine; 1- (3-phenoxy-4-pyridinyl) piperazine; 1- (2-pyridinyl) -4- (3- (2,3,4-trimethoxyphenyl) acryloyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (2-pyridinyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (4-methoxyphenyl) piperazine; 1,4-bis- (2-pyridylmethyleneamino) -piperazine; (1,4-di (2-furoyl) piperazin-1-yl) piperazine, 1,4-bis- (3,4,5-trimethoxybenzylideneamino- Bis (2- (2-pyridinyl) ethyl) piperazine, 1,4-bis [2- (4-pyridinyl) ethyl] piperazine, (3-pyridinylmethyl) piperazine, 1- (ethoxycarbonylmethyl) piperazine, 2,3,5,6-tetrahydroxy-piperazine-1,4-dicar Diethyl 2,2 '- (piperazine-1,4-diyl) bis (2-oxoacetate); diethyl 2,2' - (2E, 2'E) -3,3 '- (piperazine-1,4-diyl) diacetate; dimethyl 3,3' (2-hydroxyphenyl) prop-2-en-1-one); 2,2 '- (piperazine-1,4-diyl) bis 2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) acetamide); 2,2 '- (piperazine- (Piperazine-1,4-diyl) bis (1- (9H-carbazol-9-yl) Propane-2-ol) fumarate, 3,3 '- (piperazine-1,4-diyl) bis (1-phenylpropan- 4,4'- (piperazine-1,4-diyl) bis (3-ethoxycyclobut-3-en-1,2-dione; piperazine- Di-tert-butyl-piperazine-2,5-dione, 1,4-didodecyl-piperazine, 1,4-dihexadecyl-piperazine, 1- 1- (3-pyridinylcarbonyl) piperazine, 1- (3-pyridinylcarbonyl) piperazine, 1- (R) -3-methyl-2-ketopiperazine; 4- (Boc-piperazin-l- (Piperazin-1, 4-diyl) bis (1-phenyl-1,4-diyl) Ethanol); 2,2 '- (piperazine-1,4-diyl) bis (2- Lt; / RTI > Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; Citric acid sesquipiperazine salt hydrate; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; Escropipate; 1-piperazine propanol; t-butyl-4- (2-amino-1-phenylethyl) piperazine carboxylate; Tert-butyl 4- [2- (aminomethyl) phenyl] piperazine-1-carboxylate; Tert-butyl 4- [5- (hydroxymethyl) pyrid-2-yl] piperazine-1-carboxylate; Tert-butyl 4- (3-aminobenzyl) piperazine-1-carboxylate; Tert-butyl 4- (4 - [(methylamino) methyl] phenyl) piperazine-1-carboxylate; Tert-butyl 4- (4-cyanopyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (5-formylpyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (oxetan-3-yl) piperazine-1-carboxylate; Tert-Butyl 4- (piperidin-3-yl) piperazine-1-carboxylate; Tert-butyl 4- (pyrrolidin-2-ylcarbonyl) piperazine-1-carboxylate; Tert-Butyl 4- (lH-pyrrolo [2,3-b] pyridin-4-yl) piperazine-1-carboxylate; 1- [2- (2,5-dimethyl-1H-pyrrol-1-yl) ethyl] piperazine; 1 - ((1,5-dimethyl-1H-pyrazol-4-yl) methyl) piperazine; L- (l-Ethyl-5-methyl-lH-pyrazol-4-ylmethyl) -piperazine; t-butyl 4- (2-amino-1- [4- (trifluoromethyl) phenyl] ethyl) piperazinecarboxylate; 3- (4-Fluoro-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3- (4-Hydroxy-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3-furan-2-yl-piperazine-1-carboxylic acid tert-butyl ester; 3-thiophen-2-yl-piperazine-1-carboxylic acid benzyl ester; 4- (2-Amino-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 4- (2-aminoethyl) -1-boc-piperazine; 4- (5-Carboxy-pyridin-2-yl) -2-methyl-piperazine-1-carboxylic acid tert-butyl ester; 4-Boc-l- (6-methyl-2-pyridyl) piperazine; Fmoc-4-carboxymethyl-piperazine; Methyl 4-Boc-piperazine-2-carboxylate; N, N-dimethyl-1-piperazinesulfonamide; N-1-Boc-N-4-Fmoc-2-piperazinecarboxylic acid; N-4-Boc-N-1-cbz-2-piperazinecarboxylic acid; N-4-Boc-N-1-Fmoc-2-piperazineacetic acid; A sulfuric acid compound having piperazine-1-carboximidamide (1: 1); 1-ethyl-4-piperidin-4-yl-piperazine; 1-furan-2-ylmethyl-piperazine; L-Methyl-4- (2-piperidin-4-yl-ethyl) -piperazine; 1-Methyl-4- (6-aminopyridin-3-yl) piperazine; 1-Methyl-4- (piperidin-4-yl) -piperazine; 1-N-Boc-4- (Azetidin-3-yl) piperazine; 1-pyridin-2-ylmethyl-piperazine; 1-pyridin-3-ylmethyl-piperazine; 1 -thiazol-2-yl-piperazine; 2- (2,5-dimethoxy-phenyl) -piperazine; 2-carboxymethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; 2-ethoxycarbonylmethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; L- (4-Methyl-cyclohexyl) -piperazine; L- (4-Methyl-piperidine-l-sulfonyl) -piperazine; L- (4-Trifluoromethyl-pyridin-2-yl) -piperazine; 1- (5-methyl-2-pyridinyl) piperazine; 1- (5-methyl-2-thiazolyl) -piperazine; 1- (5-nitropyridin-2-yl) piperazine; 1- (6-butoxy-2-pyridinyl) piperazine; 1- (6-methylpyrid-2-yl) piperazine; 1- (N-methylpiperidin-3-yl-methyl) piperazine; 1- (thien-2-ylacetyl) piperazine; 1-Boc-4- (piperidin-4-yl) -piperazine; 1-Boc-4-cyanomethylpiperazine; 1-cyclohex-3-enylmethyl-piperazine, and combinations thereof. 2. A compound according to claim 1, wherein the piperazine derivative is
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 2-isobutyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (6-pyridazinyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (2-pyridyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2-ethoxyethyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-pyridylmethyl) -piperazine; 1- (ethanesulfonyl) piperazine; 3-oxo-piperazine-2-carboxylic acid; 4-methylpiperazine-1-carboxylate; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; 1,4-bis (3-pyridinylmethyl) piperazine; 1- (ethoxycarbonylmethyl) piperazine; 2,3,5,6-Tetrahydroxy-piperazine-1,4-dicarbaldehyde; Dimethyl 3,3 '- (piperazine-1,4-diyl) dipropanoate; 2,2 '-( piperazine-1,4-diyl) < / RTI > 2,2 '- (piperazine-1,4-diyl) dipropanenitrile; (R) -3-methyl-2-ketopiperazine; 2,2 '- (Piperazine-1,4-diyl) bis (2-methylpropanenitrile); Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; And combinations thereof. The tungsten chemical mechanical polishing (CMP) composition of claim 1, The composition of claim 1, wherein the piperazine derivative is selected from the group consisting of mono-substituted 1- (2-aminoethyl) piperazine, bis-substituted 1,4-bis (3-aminopropyl) piperazine, Tungsten chemical mechanical polishing (CMP) composition. The tungsten chemical mechanical polishing (CMP) composition of claim 1, wherein the chemical additive is a salt of a cyanate selected from the group consisting of potassium cyanate, sodium cyanate, ammonium cyanate, alkylammonium cyanate, and combinations thereof. The method according to claim 1,
Corrosion inhibitors;
pH buffering agents;
Surfactants; And
A biocide (when the pH of the polishing composition is 5.0 to 8.0)
≪ / RTI > further comprising one or more of the following: a) a tungsten chemical mechanical polishing (CMP) composition; the method comprising: a) providing a semiconductor substrate having a surface containing tungsten and one or more other materials;
b) providing a polishing pad;
c) providing a chemical mechanical polishing (CMP) composition;
d) contacting the surface of the semiconductor substrate with a polishing pad and a chemical mechanical polishing composition; And
e) polishing the surface of the semiconductor substrate
A method of selective chemical and mechanical polishing, comprising:
A chemical mechanical polishing (CMP) composition
1) 0.1% to 25% by weight nano-sized abrasive selected from the group consisting of silica, alumina, ceria, titania, zirconia, and combinations thereof;
2) from 0.1% to 0.5% by weight of iron compound coated particles selected from the group consisting of iron compound coated colloidal silica, iron compound-coated colloidal or nano sized inorganic metal oxide particles and combinations thereof Solid catalyst;
3) 0.0001% to 0.5% by weight of a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;
4) 0.5% to 10% by weight of an oxidizing agent; And
5) a liquid carrier, wherein the pH is from about 2.0 to about 8.0,
Some or all of the surface containing tungsten is contacted with both the polishing pad and the chemical mechanical polishing composition,
Wherein the ratio of the removal rate of tungsten to the removal rate of one or more other materials is 1 or greater. The method of claim 9, wherein the chemical additive is a piperazine derivative having the following general molecular formula:

Wherein R ₁ and R ₂ are selected from the group consisting of hydrogen, aryl, aralkyl, alkyl, alkoxy, an organic group having at least one hydroxyl group, a substituted organic sulfonic acid, a substituted organic sulfonic acid salt, a substituted organic carboxylic acid, Substituted carboxylic acids, organic carboxylic acid salts, substituted organic carboxylic acid amides, substituted keto, organic carboxylic acid esters, organic amines, and combinations thereof. The method of claim 9, wherein the tungsten-containing semiconductor substrate is selected from the group consisting of (a) a substituted organic mono-aminopiperazine derivative having a piperazine derivative of the following molecular structure: (b) a substituted organobisaminopiperazine derivative, How to polish:

In this formula,
n is independently selected from 1 to 6;
R, R ', R "and R"' are independently selected from the group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, organic groups having at least one hydroxyl group, substituted organic sulfonic acids, substituted organic sulfonic acid salts, , Substituted organic carboxylic acid salts, substituted keto, organic carboxylic acid esters, organic amines, substituted organic carboxylic acid amides, and combinations thereof. 10. The composition of claim 9, wherein the chemical additive is
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4-Boc-Piperazine-2-carboxylic acid; 1- (diphenylmethyl) piperazine; 1,4-di-Boc-piperazine-2-carboxylic acid; 2- (Piperazine-1-carbonyl) -benzoic acid; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid (2-chloro-phenyl) -amide Piperazine-1-carboxylic acid dimethylamide; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-carboxylic acid diphenylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 1- (2-butyl) -piperazine; 2-isobutyl-piperazine; 2,3-tert-butylpiperazine; r-2-isobutyl-piperazine; s-2-isobutyl-piperazine; 2-isopropyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (4-Trifluoromethylphenyl) piperazine; 1- (cyclopropylmethyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (2-Trifluoromethylphenyl) -piperazine; 1- (6-pyridazinyl) piperazine; 2- (4-trifluoromethylphenyl) piperazine; 2-phenyl-piperazine-1-carboxylic acid benzyl ester; 1- (1-naphthylmethyl) piperazine; 1- (1-pentyl) piperazine; 1- (2-pentyl) -piperazine; 1- (3-Pentyl) -piperazine; 1- (propanoyl) -piperazine; 2-phenyl-piperazine-1-carboxylic acid tert-butyl ester; 1-Boc-piperazine; 1- (4-chlorophenyl) piperazine; 1- (2-furoyl) piperazine; 1- (2-fluorophenyl) piperazine; 1- (2-hydroxyphenyl) piperazine; 1- (2-phenylethyl) piperazine; 1- (4-fluorophenyl) piperazine; 1- (2-methylbenzyl) piperazine; 1- (4-hydroxyphenyl) piperazine; 1- (4-methylbenzyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (1-phenylethyl) piperazine; 1- (2,4-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,6-xylyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (3,4-dimethylphenyl) piperazine; 1- (3,5-dimethylphenyl) piperazine; 1- (3-fluorophenyl) piperazine; 1- (3-furoyl) piperazine; 1- (N-heptyl) piperazine; 1-pivaloyl-piperazine; 2,3-dimethyl-piperazine-1-carboxylic acid tert-butyl ester; 2- (2-chlorophenyl) piperazine; 2- (4-chlorophenyl) piperazine; n-4-cbz-piperazine-2-carboxylate methyl ester; 1- (2-pyridyl) piperazine; 1- (2-methoxyphenyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-chlorobenzhydryl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (1-adamantyl) piperazine; 1- (4-nitrophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 2- (trifluoromethyl) piperazine; 1- (3,4-dichlorophenyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2,5-difluorobenzyl) piperazine; 1- (2-ethoxyethyl) piperazine; 1- (3,4-dichlorobenzyl) piperazine; 1- (3-methoxyphenyl) piperazine; 1- (cyclohexylmethyl) piperazine; 1- (3-methylphenyl) piperazine; 1- (4-methylphenyl) piperazine; 1- (3-fluorobenzyl) piperazine; 1- (4-fluorobenzyl) piperazine; 2- (3-methoxyphenyl) piperazine; 1- (3-chlorobenzyl) piperazine; 1- (Cyclopropylcarbonyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -2-benzyl-piperazine; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; S) -2-benzyl-piperazine; (S) -2-Benzyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2,2,2-trifluoroethyl) piperazine; 1- (2,3-difluorophenyl) piperazine; 1- (2,4,6-trimethylbenzyl) piperazine; 1- (2,4-dichlorobenzyl) piperazine; 1- (2,4-difluorophenyl) piperazine; 1- (2,6-dichlorobenzyl) piperazine; 1- (2-chlorobenzyl) piperazine; 1- (2-cyclohexylethyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-fluorobenzyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-phenoxyethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3,3-dimethylbutanoyl) piperazine; 1- (3,4-dichlorobenzoyl) piperazine; 1- (3- (3,5-dichlorophenyl) piperazine; 4-difluorobenzoyl) piperazine; 1- (3,4-dimethylbenzyl) piperazine; 1- (3,5-dimethoxybenzoyl) piperazine; 1- (3,5-dimethylbenzoyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-phenylpropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-chlorobenzoyl) piperazine; 1- (4-chlorobenzyl) piperazine; 1- (4-ethoxyphenyl) piperazine; 1- (4-methoxybenzoyl) -piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-phenylbutyl) -piperazine; 1- (4-pyridylmethyl) piperazine; 1- (4- tert -butylbenzyl) piperazine; 1- (cyclohexylcarbonyl) piperazine; 1- (ethanesulfonyl) piperazine; 1- (phenylacetyl) piperazine; 1-cbz-piperazine-2-carboxylic acid; 1-hexanoyl-piperazine; 1-methylsulfonyl-piperazine; 2,3-diphenyl-piperazine; 2- (2-furyl) piperazine; 2- (2-methoxyphenyl) piperazine; 2- (2-thienyl) piperazine; 2- (3-oxo-piperazine-1-carbonyl) -benzoic acid; 2- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 2- (4-methoxyphenyl) piperazine; 2- (4-methylphenyl) piperazine; 2-benzyl-piperazine; 3- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 3-oxo-piperazine-2-carboxylic acid; 3-phenyl-piperazine-1-carboxylic acid ethyl ester; 4- (4-Boc-piperazine-1-carbonyl) phenylboronic acid pinacol ester; [5- (4-Methyl-piperazine-l-sulfonyl) -pyridin-2-yl] -hydrazine; Methylpiperazine-1-carboxylate; 1-ethyl-2-methyl-piperazine; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 1- (2-methyl-allyl) -piperazine; 2- (3-Trifluoromethyl-phenyl) -piperazine; 4-N-Boc-2-methyl-piperazine; 1- (Tetrahydro-2-furoyl) -piperazine; 1- (tetrahydro-2-furylmethyl) piperazine; (R) -l-Boc-2-ethyl-piperazine; (R) -l-Boc-3-ethyl-piperazine; (S) -l-Boc-2-ethyl-piperazine; (S) -l-Boc-3-ethyl-piperazine; 1- [1- (2-methoxyphenyl) ethyl] piperazine; 1- [1- (3-methoxyphenyl) ethyl] piperazine; 1- [1- (4-methoxyphenyl) -ethyl] -piperazine; 1- [2- (2-methylphenoxy) ethyl] piperazine; 1- (4-ethoxy-benzyl) -piperazine; 1-Boc-2,6-dimethyl-piperazine; 1-Boc-3,3-dimethyl-piperazine; 1-Boc-3,5-dimethyl-piperazine; 1-Boc-5-oxo-piperazine-2-carboxylic acid; 1-N- (tert-butoxycarbonyl) -2-ethyl-piperazine; 2- (2-fluoro-phenyl) -piperazine; 2- (3-Fluoro-phenyl) -piperazine; 2-methyl-1- (3-methylphenyl) piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-acetyl-4- (4-hydroxyphenyl) piperazine; 1- [4- (trifluoromethyl) benzyl] piperazine; 1-Boc-4- (2-formylphenyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1-Boc- (4-benzyl) piperazine; 1-Boc-4- [3- (ethoxycarbonyl) phenyl] piperazine; 1-bis (4-fluorophenyl) methylpiperazine; 1-Boc-4- (3-hydroxypropyl) piperazine; 1-Boc-4- (4-formylphenyl) piperazine; 1-Boc-4- (4-methoxycarbonylphenyl) piperazine; 1- (1,3-dioxolan-2-ylmethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (1,2,3,4-tetrahydronaphthalen-2-yl) piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1-Boc-4- (2-methoxycarbonylphenyl) piperazine; 1-Boc-4- (5-nitro-2-pyridyl) piperazine; (R) -l-Boc-2-benzyl-piperazine; (R) -l-N-Boc-2-isopropylpiperazine; (R) -l-N-Boc-4-N-Fmoc-2-piperazinecarboxylic acid; (R) -l-N-cbz-2-methyl-piperazine; (R) -4-N-trityl-2-methylpiperazine; (R) -N4-benzyl-2- (benzyloxymethyl) piperazine; (S) -l-Boc-2-hydroxymethyl-piperazine; (S) -l-Boc-2-isobutyl-piperazine; (S) -l-Boc-3-benzyl-piperazine; (S) -l-Boc-3-isopropyl-piperazine; (S) -l-N-Boc-4-N-Fmoc-Piperazine-2-carboxylic acid; (S) -4-N-trityl-2-methyl-piperazine; (S) -n4-benzyl-2- (methylthioethyl) piperazine; 1 - [(2,6-dichlorophenyl) sulfonyl] piperazine; 1 - [(2-methyl-1,3-thiazol-5-yl) methyl] piperazine; 1 - [(4,5-dimethyl-1,3-oxazol-2-yl) methyl] piperazine; 1 - [(4-cyclohexylphenyl) sulfonyl] piperazine; 1 - [(4-isobutylphenyl) sulfonyl] piperazine; 1 - [(4-methyl-1,2,5-oxadiazol-3-yl) methyl] piperazine; 1 - [(4-tert-butylphenyl) sulfonyl] piperazine; 1 - [(4-tert-butyl-2,6-dimethylphenyl) sulfonyl] piperazine; 1- [1- (Pyridin-2-yl) ethyl] piperazine; 1- [1- (Pyridin-3-yl) ethyl] piperazine; 1- [1- (thiophen-2-yl) ethyl] piperazine; 1- [2- (1-propyl) -oxyethyl] -piperazine; 1- [2- (1H-pyrrol-1-yl) ethyl] piperazine; L- [2- (2-Methoxy-phenoxy) -ethyl] -piperazine; 1- [2- (Diallylamino) -ethyl] -piperazine; 1- [2- (trifluoromethyl) pyridin-4-yl] piperazine; 1- [2- (trifluoromethyl) quinol-4-yl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] -4- (2-hydroxyethyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- [3- (difluoromethoxy) benzoyl] piperazine; 1- [3- (trifluoromethyl) pyrid-2-yl] piperazine; 1- [4- (methylsulfonyl) phenyl] piperazine; 1- [4- (trifluoromethyl) pyrimido-2-yl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-Benzhydryloxy-ethyl) -piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (2-methyl-thiazol-4-ylmethyl) -piperazine; 1- (2-N-Boc-aminoethyl) piperazine; 1- (2-pyridin-2-yl-ethyl) -piperazine; 1- (2-pyridin-4-yl-ethyl) -piperazine; 1- (2-thiophen-2-yl-ethyl) piperazine; L- (3,5-Dimethyl-isoxazol-4-ylmethyl) -piperazine; 1- (3-Methoxy-benzyl) -piperazine; 1- (3-methyl-benzoyl) -piperazine; L- (3-Methyl-pyridin-2-ylmethyl) -piperazine; 1- (3-methylpyridin-2-yl) piperazine; 1- (3-methylpyridin-4-yl) piperazine; 1- (4,6-dimethylpyrimidin-2-yl) piperazine; 1- (4-Cyano-benzyl) -piperazine; 1- (4-Ethoxy-benzenesulfonyl) -piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 1- (4-fluorobenzyl) -4- (2-hydroxyethyl) piperazine; 1- (4-Hydroxy-phenyl) -piperazine-4-carboxylic acid tert-butyl ester; (Currently 14 pages) N-Boc-piperidine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; (R) -1-Boc-3-methylpiperazine; 1-Boc-3-oxopiperazine; 1,4-Bis- (2-methoxy-5-methyl-benzenesulfonyl) -2-methyl-piperazine; 1 - [(1-methyl-1H-pyrazol-3-yl) carbonyl] piperazine; 1 - [(1-methyl-1H-pyrazol-4-yl) methyl] piperazine; 1- (2- (N, N-bis- (2-hydroxypropyl) -amino) -ethyl) -4- (2-hydroxypropyl) -piperazine; 1- (2-methoxyphenyl) -4 - ((4- (2-methoxyphenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (3- (2,3-dihydro-1,4-benzodioxin-6-yl) acryloyl) -4- (4-fluorophenyl) piperazine; Sulfonyl} -9H-fluoren-2-yl) sulfonyl] piperazine < / RTI >; 1- (4-Fluorophenyl) -4 - ((4- (4-fluorophenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (4-Nitrophenyl) -4- (3 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; 1- (4-Nitrophenyl) -4- (4 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; L-acetyl-4- (l-ethyl-lH-imidazol-2-yl) piperazine; Yl} ethyl) -1H-pyrazol-3-yl] -1H-pyrazolo [3,4-d] Piperazine; L-benzyl-4- [2 - [(2 ', 4'-difluoro [1,1'-biphenyl] -4-yl) oxy] ethyl] piperazine; 1-Benzyl-4- (3 - ((2 ', 4'-difluoro (1,1'-biphenyl) -4-yl) oxy) propyl) piperazine; L-isopropyl-4 - [(l-methyl-lH-pyrrol-2-yl) methyl] piperazine; 1 -Methyl-4 - ({7 - [(4-methyl-1-piperazinyl) sulfonyl] -9H-fluoren-2-yl} sulfonyl) piperazine; 1-phenyl-4- [phenyl (4-phenyl-1-piperazinyl) methyl] piperazine; 1-methyl-4- (methylsulfonyl) piperazine; 4- (2-Hydroxy-ethyl) -piperazine-l-carboxylic acid (4-isopropyl-phenyl) -amide; 6-hydroxymethyl-l, 3-dimethyl-piperazine-2,5-dione; Bis (2-methoxyphenyl) 2,2 '- (piperazine-1,4-diyl) diethanesulfonate; 1- (adamantane-1-sulfinyl) -4-methyl-piperazine; 1- (phenylsulfonyl) -4- (2-pyridinyl) piperazine; 1-benzyl-4- (2-methoxypropanoyl) piperazine; 1-cyclohexyl-4- (methylsulfonyl) piperazine; 1-ethyl-4- (3-furylmethyl) piperazine; 1- (3-phenoxy-4-pyridinyl) piperazine; 1- (2-pyridinyl) -4- (3- (2,3,4-trimethoxyphenyl) acryloyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (2-pyridinyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (4-methoxyphenyl) piperazine; 1,4-bis- (2-pyridylmethyleneamino) -piperazine; (1,4-di (2-furoyl) piperazin-1-yl) piperazine, 1,4-bis- (3,4,5-trimethoxybenzylideneamino- Bis (2- (2-pyridinyl) ethyl) piperazine, 1,4-bis [2- (4-pyridinyl) ethyl] piperazine, (3-pyridinylmethyl) piperazine, 1- (ethoxycarbonylmethyl) piperazine, 2,3,5,6-tetrahydroxy-piperazine-1,4-dicar Diethyl 2,2 '- (piperazine-1,4-diyl) bis (2-oxoacetate); diethyl 2,2' - (2E, 2'E) -3,3 '- (piperazine-1,4-diyl) diacetate; dimethyl 3,3' (2-hydroxyphenyl) prop-2-en-1-one); 2,2 '- (piperazine-1,4-diyl) bis 2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) acetamide); 2,2 '- (piperazine- (Piperazine-1,4-diyl) bis (1- (9H-carbazol-9-yl) Propane-2-ol) fumarate, 3,3 '- (piperazine-1,4-diyl) bis (1-phenylpropan- 4,4'- (piperazine-1,4-diyl) bis (3-ethoxycyclobut-3-en-1,2-dione; piperazine- Di-tert-butyl-piperazine-2,5-dione, 1,4-didodecyl-piperazine, 1,4-dihexadecyl-piperazine, 1- 1- (3-pyridinylcarbonyl) piperazine, 1- (3-pyridinylcarbonyl) piperazine, 1- (R) -3-methyl-2-ketopiperazine; 4- (Boc-piperazin-l- (Piperazin-1, 4-diyl) bis (1-phenyl-1,4-diyl) Ethanol); 2,2 '- (piperazine-1,4-diyl) bis (2- Lt; / RTI > Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; Citric acid sesquipiperazine salt hydrate; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; Escropipate; 1-piperazine propanol; t-butyl-4- (2-amino-1-phenylethyl) piperazine carboxylate; Tert-butyl 4- [2- (aminomethyl) phenyl] piperazine-1-carboxylate; Tert-butyl 4- [5- (hydroxymethyl) pyrid-2-yl] piperazine-1-carboxylate; Tert-butyl 4- (3-aminobenzyl) piperazine-1-carboxylate; Tert-butyl 4- (4 - [(methylamino) methyl] phenyl) piperazine-1-carboxylate; Tert-butyl 4- (4-cyanopyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (5-formylpyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (oxetan-3-yl) piperazine-1-carboxylate; Tert-Butyl 4- (piperidin-3-yl) piperazine-1-carboxylate; Tert-butyl 4- (pyrrolidin-2-ylcarbonyl) piperazine-1-carboxylate; Tert-Butyl 4- (lH-pyrrolo [2,3-b] pyridin-4-yl) piperazine-1-carboxylate; 1- [2- (2,5-dimethyl-1H-pyrrol-1-yl) ethyl] piperazine; 1 - ((1,5-dimethyl-1H-pyrazol-4-yl) methyl) piperazine; L- (l-Ethyl-5-methyl-lH-pyrazol-4-ylmethyl) -piperazine; t-butyl 4- (2-amino-1- [4- (trifluoromethyl) phenyl] ethyl) piperazinecarboxylate; 3- (4-Fluoro-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3- (4-Hydroxy-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3-furan-2-yl-piperazine-1-carboxylic acid tert-butyl ester; 3-thiophen-2-yl-piperazine-1-carboxylic acid benzyl ester; 4- (2-Amino-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 4- (2-aminoethyl) -1-boc-piperazine; 4- (5-Carboxy-pyridin-2-yl) -2-methyl-piperazine-1-carboxylic acid tert-butyl ester; 4-Boc-l- (6-methyl-2-pyridyl) piperazine; Fmoc-4-carboxymethyl-piperazine; Methyl 4-Boc-piperazine-2-carboxylate; N, N-dimethyl-1-piperazinesulfonamide; N-1-Boc-N-4-Fmoc-2-piperazinecarboxylic acid; N-4-Boc-N-1-cbz-2-piperazinecarboxylic acid; N-4-Boc-N-1-Fmoc-2-piperazineacetic acid; A sulfuric acid compound having piperazine-1-carboximidamide (1: 1); 1-ethyl-4-piperidin-4-yl-piperazine; 1-furan-2-ylmethyl-piperazine; L-Methyl-4- (2-piperidin-4-yl-ethyl) -piperazine; 1-Methyl-4- (6-aminopyridin-3-yl) piperazine; 1-Methyl-4- (piperidin-4-yl) -piperazine; 1-N-Boc-4- (Azetidin-3-yl) piperazine; 1-pyridin-2-ylmethyl-piperazine; 1-pyridin-3-ylmethyl-piperazine; 1 -thiazol-2-yl-piperazine; 2- (2,5-dimethoxy-phenyl) -piperazine; 2-carboxymethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; 2-ethoxycarbonylmethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; L- (4-Methyl-cyclohexyl) -piperazine; L- (4-Methyl-piperidine-l-sulfonyl) -piperazine; L- (4-Trifluoromethyl-pyridin-2-yl) -piperazine; 1- (5-methyl-2-pyridinyl) piperazine; 1- (5-methyl-2-thiazolyl) -piperazine; 1- (5-nitropyridin-2-yl) piperazine; 1- (6-butoxy-2-pyridinyl) piperazine; 1- (6-methylpyrid-2-yl) piperazine; 1- (N-methylpiperidin-3-yl-methyl) piperazine; 1- (thien-2-ylacetyl) piperazine; 1-Boc-4- (piperidin-4-yl) -piperazine; 1-Boc-4-cyanomethylpiperazine; 1-cyclohex-3-enylmethyl-piperazine, and combinations thereof. ≪ RTI ID = 0.0 > 11. < / RTI > 10. A compound according to claim 9, wherein the piperazine derivative is
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 2-isobutyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (6-pyridazinyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (2-pyridyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2-ethoxyethyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-pyridylmethyl) -piperazine; 1- (ethanesulfonyl) piperazine; 3-oxo-piperazine-2-carboxylic acid; 4-methylpiperazine-1-carboxylate; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; 1,4-bis (3-pyridinylmethyl) piperazine; 1- (ethoxycarbonylmethyl) piperazine; 2,3,5,6-Tetrahydroxy-piperazine-1,4-dicarbaldehyde; Dimethyl 3,3 '- (piperazine-1,4-diyl) dipropanoate; 2,2 '-( piperazine-1,4-diyl) < / RTI > 2,2 '- (piperazine-1,4-diyl) dipropanenitrile; (R) -3-methyl-2-ketopiperazine; 2,2 '- (Piperazine-1,4-diyl) bis (2-methylpropanenitrile); Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; And combinations thereof. ≪ RTI ID = 0.0 > 11. < / RTI > 10. The composition of claim 9 wherein the chemical additive is selected from the group consisting of mono-substituted 1- (2-aminoethyl) piperazine, bis-substituted 1,4-bis (3-aminopropyl) piperazine, ≪ / RTI > wherein the tungsten-containing semiconductor substrate is a piperazine derivative selected from the group consisting of: 10. The method of claim 9, wherein the chemical additive is a salt of cyanate selected from the group consisting of potassium cyanate, sodium cyanate, ammonium cyanate, alkylammonium cyanate, and combinations thereof, wherein the tungsten- How to. The method of claim 9, wherein the chemical mechanical polishing (CMP) composition comprises
Corrosion inhibitors;
pH buffering agents;
Surfactants; And
A biocide (when the pH of the polishing composition is 5.0 to 8.0)
≪ / RTI > further comprising at least one of the following: < RTI ID = 0.0 > a) a semiconductor substrate having a surface containing tungsten and one or more other materials;
b) a polishing pad; And
c) chemical mechanical polishing (CMP) composition
A selective chemical mechanical polishing system comprising:
A chemical mechanical polishing (CMP) composition
1) 0.1% to 25% by weight nano-sized abrasive selected from the group consisting of silica, alumina, ceria, titania, zirconia, and combinations thereof;
2) from 0.1% to 0.5% by weight of iron compound coated particles selected from the group consisting of iron compound coated colloidal silica, iron compound-coated colloidal or nano sized inorganic metal oxide particles and combinations thereof Solid catalyst;
3) 0.0001% to 0.5% by weight of a chemical additive selected from the group consisting of piperazine derivatives, salts of cyanates, and combinations thereof;
4) 0.5% to 10% by weight of an oxidizing agent; And
5) a liquid carrier, wherein the pH is from about 2.0 to about 8.0,
Wherein some or all of the surface containing tungsten is contacted with both the polishing pad and the chemical mechanical polishing composition. 18. The selective chemical mechanical polishing system of claim 17, wherein the chemical additive is a piperazine derivative having the following general molecular formula:

Wherein R ₁ and R ₂ are selected from the group consisting of hydrogen, aryl, aralkyl, alkyl, alkoxy, an organic group having at least one hydroxyl group, a substituted organic sulfonic acid, a substituted organic sulfonic acid salt, a substituted organic carboxylic acid, Substituted carboxylic acids, organic carboxylic acid salts, substituted organic carboxylic acid amides, substituted keto, organic carboxylic acid esters, organic amines, and combinations thereof. 18. A selective chemical mechanical polishing system according to claim 17, wherein the piperazine derivative is a substituted organic mono-aminopiperazine derivative (a) or a substituted organic bis-aminopiperazine derivative (b) having the following molecular formula:

In this formula,
n is independently selected from 1 to 6;
R, R ', R "and R"' are independently selected from the group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, organic groups having at least one hydroxyl group, substituted organic sulfonic acids, substituted organic sulfonic acid salts, , Substituted organic carboxylic acid salts, organic carboxylic acid esters, organic amines, substituted organic carboxylic acid amides, and combinations thereof. 18. The composition of claim 17, wherein the chemical additive comprises
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4-Boc-Piperazine-2-carboxylic acid; 1- (diphenylmethyl) piperazine; 1,4-di-Boc-piperazine-2-carboxylic acid; 2- (Piperazine-1-carbonyl) -benzoic acid; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid (2-chloro-phenyl) -amide Piperazine-1-carboxylic acid dimethylamide; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-carboxylic acid diphenylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 1- (2-butyl) -piperazine; 2-isobutyl-piperazine; 2,3-tert-butylpiperazine; r-2-isobutyl-piperazine; s-2-isobutyl-piperazine; 2-isopropyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (4-Trifluoromethylphenyl) piperazine; 1- (cyclopropylmethyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (2-Trifluoromethylphenyl) -piperazine; 1- (6-pyridazinyl) piperazine; 2- (4-trifluoromethylphenyl) piperazine; 2-phenyl-piperazine-1-carboxylic acid benzyl ester; 1- (1-naphthylmethyl) piperazine; 1- (1-pentyl) piperazine; 1- (2-pentyl) -piperazine; 1- (3-Pentyl) -piperazine; 1- (propanoyl) -piperazine; 2-phenyl-piperazine-1-carboxylic acid tert-butyl ester; 1-Boc-piperazine; 1- (4-chlorophenyl) piperazine; 1- (2-furoyl) piperazine; 1- (2-fluorophenyl) piperazine; 1- (2-hydroxyphenyl) piperazine; 1- (2-phenylethyl) piperazine; 1- (4-fluorophenyl) piperazine; 1- (2-methylbenzyl) piperazine; 1- (4-hydroxyphenyl) piperazine; 1- (4-methylbenzyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (1-phenylethyl) piperazine; 1- (2,4-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,5-dimethylphenyl) piperazine; 1- (2,6-xylyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (2-ethylphenyl) piperazine; 1- (3,4-dimethylphenyl) piperazine; 1- (3,5-dimethylphenyl) piperazine; 1- (3-fluorophenyl) piperazine; 1- (3-furoyl) piperazine; 1- (N-heptyl) piperazine; 1-pivaloyl-piperazine; 2,3-dimethyl-piperazine-1-carboxylic acid tert-butyl ester; 2- (2-chlorophenyl) piperazine; 2- (4-chlorophenyl) piperazine; n-4-cbz-piperazine-2-carboxylate methyl ester; 1- (2-pyridyl) piperazine; 1- (2-methoxyphenyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-chlorobenzhydryl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (1-adamantyl) piperazine; 1- (4-nitrophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 2- (trifluoromethyl) piperazine; 1- (3,4-dichlorophenyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2,5-difluorobenzyl) piperazine; 1- (2-ethoxyethyl) piperazine; 1- (3,4-dichlorobenzyl) piperazine; 1- (3-methoxyphenyl) piperazine; 1- (cyclohexylmethyl) piperazine; 1- (3-methylphenyl) piperazine; 1- (4-methylphenyl) piperazine; 1- (3-fluorobenzyl) piperazine; 1- (4-fluorobenzyl) piperazine; 2- (3-methoxyphenyl) piperazine; 1- (3-chlorobenzyl) piperazine; 1- (Cyclopropylcarbonyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -2-benzyl-piperazine; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; S) -2-benzyl-piperazine; (S) -2-Benzyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2,2,2-trifluoroethyl) piperazine; 1- (2,3-difluorophenyl) piperazine; 1- (2,4,6-trimethylbenzyl) piperazine; 1- (2,4-dichlorobenzyl) piperazine; 1- (2,4-difluorophenyl) piperazine; 1- (2,6-dichlorobenzyl) piperazine; 1- (2-chlorobenzyl) piperazine; 1- (2-cyclohexylethyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-fluorobenzyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-phenoxyethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3,3-dimethylbutanoyl) piperazine; 1- (3,4-dichlorobenzoyl) piperazine; 1- (3- (3,5-dichlorophenyl) piperazine; 4-difluorobenzoyl) piperazine; 1- (3,4-dimethylbenzyl) piperazine; 1- (3,5-dimethoxybenzoyl) piperazine; 1- (3,5-dimethylbenzoyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-phenylpropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-chlorobenzoyl) piperazine; 1- (4-chlorobenzyl) piperazine; 1- (4-ethoxyphenyl) piperazine; 1- (4-methoxybenzoyl) -piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-phenylbutyl) -piperazine; 1- (4-pyridylmethyl) piperazine; 1- (4- tert -butylbenzyl) piperazine; 1- (cyclohexylcarbonyl) piperazine; 1- (ethanesulfonyl) piperazine; 1- (phenylacetyl) piperazine; 1-cbz-piperazine-2-carboxylic acid; 1-hexanoyl-piperazine; 1-methylsulfonyl-piperazine; 2,3-diphenyl-piperazine; 2- (2-furyl) piperazine; 2- (2-methoxyphenyl) piperazine; 2- (2-thienyl) piperazine; 2- (3-oxo-piperazine-1-carbonyl) -benzoic acid; 2- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 2- (4-methoxyphenyl) piperazine; 2- (4-methylphenyl) piperazine; 2-benzyl-piperazine; 3- (4-Chlorophenyl) piperazine-1-carboxylic acid tert-butyl ester; 3-oxo-piperazine-2-carboxylic acid; 3-phenyl-piperazine-1-carboxylic acid ethyl ester; 4- (4-Boc-piperazine-1-carbonyl) phenylboronic acid pinacol ester; [5- (4-Methyl-piperazine-l-sulfonyl) -pyridin-2-yl] -hydrazine; Methylpiperazine-1-carboxylate; 1-ethyl-2-methyl-piperazine; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 1- (2-methyl-allyl) -piperazine; 2- (3-Trifluoromethyl-phenyl) -piperazine; 4-N-Boc-2-methyl-piperazine; 1- (Tetrahydro-2-furoyl) -piperazine; 1- (tetrahydro-2-furylmethyl) piperazine; (R) -l-Boc-2-ethyl-piperazine; (R) -l-Boc-3-ethyl-piperazine; (S) -l-Boc-2-ethyl-piperazine; (S) -l-Boc-3-ethyl-piperazine; 1- [1- (2-methoxyphenyl) ethyl] piperazine; 1- [1- (3-methoxyphenyl) ethyl] piperazine; 1- [1- (4-methoxyphenyl) -ethyl] -piperazine; 1- [2- (2-methylphenoxy) ethyl] piperazine; 1- (4-ethoxy-benzyl) -piperazine; 1-Boc-2,6-dimethyl-piperazine; 1-Boc-3,3-dimethyl-piperazine; 1-Boc-3,5-dimethyl-piperazine; 1-Boc-5-oxo-piperazine-2-carboxylic acid; 1-N- (tert-butoxycarbonyl) -2-ethyl-piperazine; 2- (2-fluoro-phenyl) -piperazine; 2- (3-Fluoro-phenyl) -piperazine; 2-methyl-1- (3-methylphenyl) piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-acetyl-4- (4-hydroxyphenyl) piperazine; 1- [4- (trifluoromethyl) benzyl] piperazine; 1-Boc-4- (2-formylphenyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1-Boc- (4-benzyl) piperazine; 1-Boc-4- [3- (ethoxycarbonyl) phenyl] piperazine; 1-bis (4-fluorophenyl) methylpiperazine; 1-Boc-4- (3-hydroxypropyl) piperazine; 1-Boc-4- (4-formylphenyl) piperazine; 1-Boc-4- (4-methoxycarbonylphenyl) piperazine; 1- (1,3-dioxolan-2-ylmethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (1,2,3,4-tetrahydronaphthalen-2-yl) piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1-Boc-4- (2-methoxycarbonylphenyl) piperazine; 1-Boc-4- (5-nitro-2-pyridyl) piperazine; (R) -l-Boc-2-benzyl-piperazine; (R) -l-N-Boc-2-isopropylpiperazine; (R) -l-N-Boc-4-N-Fmoc-2-piperazinecarboxylic acid; (R) -l-N-cbz-2-methyl-piperazine; (R) -4-N-trityl-2-methylpiperazine; (R) -N4-benzyl-2- (benzyloxymethyl) piperazine; (S) -l-Boc-2-hydroxymethyl-piperazine; (S) -l-Boc-2-isobutyl-piperazine; (S) -l-Boc-3-benzyl-piperazine; (S) -l-Boc-3-isopropyl-piperazine; (S) -l-N-Boc-4-N-Fmoc-Piperazine-2-carboxylic acid; (S) -4-N-trityl-2-methyl-piperazine; (S) -n4-benzyl-2- (methylthioethyl) piperazine; 1 - [(2,6-dichlorophenyl) sulfonyl] piperazine; 1 - [(2-methyl-1,3-thiazol-5-yl) methyl] piperazine; 1 - [(4,5-dimethyl-1,3-oxazol-2-yl) methyl] piperazine; 1 - [(4-cyclohexylphenyl) sulfonyl] piperazine; 1 - [(4-isobutylphenyl) sulfonyl] piperazine; 1 - [(4-methyl-1,2,5-oxadiazol-3-yl) methyl] piperazine; 1 - [(4-tert-butylphenyl) sulfonyl] piperazine; 1 - [(4-tert-butyl-2,6-dimethylphenyl) sulfonyl] piperazine; 1- [1- (Pyridin-2-yl) ethyl] piperazine; 1- [1- (Pyridin-3-yl) ethyl] piperazine; 1- [1- (thiophen-2-yl) ethyl] piperazine; 1- [2- (1-propyl) -oxyethyl] -piperazine; 1- [2- (1H-pyrrol-1-yl) ethyl] piperazine; L- [2- (2-Methoxy-phenoxy) -ethyl] -piperazine; 1- [2- (Diallylamino) -ethyl] -piperazine; 1- [2- (trifluoromethyl) pyridin-4-yl] piperazine; 1- [2- (trifluoromethyl) quinol-4-yl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] piperazine; 1- [2-fluoro-4- (methylsulfonyl) phenyl] -4- (2-hydroxyethyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- [3- (difluoromethoxy) benzoyl] piperazine; 1- [3- (trifluoromethyl) pyrid-2-yl] piperazine; 1- [4- (methylsulfonyl) phenyl] piperazine; 1- [4- (trifluoromethyl) pyrimido-2-yl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-Benzhydryloxy-ethyl) -piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (2-methyl-thiazol-4-ylmethyl) -piperazine; 1- (2-N-Boc-aminoethyl) piperazine; 1- (2-pyridin-2-yl-ethyl) -piperazine; 1- (2-pyridin-4-yl-ethyl) -piperazine; 1- (2-thiophen-2-yl-ethyl) piperazine; L- (3,5-Dimethyl-isoxazol-4-ylmethyl) -piperazine; 1- (3-Methoxy-benzyl) -piperazine; 1- (3-methyl-benzoyl) -piperazine; L- (3-Methyl-pyridin-2-ylmethyl) -piperazine; 1- (3-methylpyridin-2-yl) piperazine; 1- (3-methylpyridin-4-yl) piperazine; 1- (4,6-dimethylpyrimidin-2-yl) piperazine; 1- (4-Cyano-benzyl) -piperazine; 1- (4-Ethoxy-benzenesulfonyl) -piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 1- (4-fluorobenzyl) -4- (2-hydroxyethyl) piperazine; 1- (4-Hydroxy-phenyl) -piperazine-4-carboxylic acid tert-butyl ester; (Currently 14 pages) N-Boc-piperidine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; (R) -1-Boc-3-methylpiperazine; 1-Boc-3-oxopiperazine; 1,4-Bis- (2-methoxy-5-methyl-benzenesulfonyl) -2-methyl-piperazine; 1 - [(1-methyl-1H-pyrazol-3-yl) carbonyl] piperazine; 1 - [(1-methyl-1H-pyrazol-4-yl) methyl] piperazine; 1- (2- (N, N-bis- (2-hydroxypropyl) -amino) -ethyl) -4- (2-hydroxypropyl) -piperazine; 1- (2-methoxyphenyl) -4 - ((4- (2-methoxyphenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (3- (2,3-dihydro-1,4-benzodioxin-6-yl) acryloyl) -4- (4-fluorophenyl) piperazine; Sulfonyl} -9H-fluoren-2-yl) sulfonyl] piperazine < / RTI >; 1- (4-Fluorophenyl) -4 - ((4- (4-fluorophenyl) -1-piperazinyl) (oxo) acetyl) piperazine; 1- (4-Nitrophenyl) -4- (3 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; 1- (4-Nitrophenyl) -4- (4 - {[4- (4-nitrophenyl) -1-piperazinyl] carbonyl} benzoyl) piperazine; L-acetyl-4- (l-ethyl-lH-imidazol-2-yl) piperazine; Yl} ethyl) -1H-pyrazol-3-yl] -1H-pyrazolo [3,4-d] Piperazine; L-benzyl-4- [2 - [(2 ', 4'-difluoro [1,1'-biphenyl] -4-yl) oxy] ethyl] piperazine; 1-Benzyl-4- (3 - ((2 ', 4'-difluoro (1,1'-biphenyl) -4-yl) oxy) propyl) piperazine; L-isopropyl-4 - [(l-methyl-lH-pyrrol-2-yl) methyl] piperazine; 1 -Methyl-4 - ({7 - [(4-methyl-1-piperazinyl) sulfonyl] -9H-fluoren-2-yl} sulfonyl) piperazine; 1-phenyl-4- [phenyl (4-phenyl-1-piperazinyl) methyl] piperazine; 1-methyl-4- (methylsulfonyl) piperazine; 4- (2-Hydroxy-ethyl) -piperazine-l-carboxylic acid (4-isopropyl-phenyl) -amide; 6-hydroxymethyl-l, 3-dimethyl-piperazine-2,5-dione; Bis (2-methoxyphenyl) 2,2 '- (piperazine-1,4-diyl) diethanesulfonate; 1- (adamantane-1-sulfinyl) -4-methyl-piperazine; 1- (phenylsulfonyl) -4- (2-pyridinyl) piperazine; 1-benzyl-4- (2-methoxypropanoyl) piperazine; 1-cyclohexyl-4- (methylsulfonyl) piperazine; 1-ethyl-4- (3-furylmethyl) piperazine; 1- (3-phenoxy-4-pyridinyl) piperazine; 1- (2-pyridinyl) -4- (3- (2,3,4-trimethoxyphenyl) acryloyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (2-pyridinyl) piperazine; 1- (3- (1,3-benzodioxol-5-yl) acryloyl) -4- (4-methoxyphenyl) piperazine; 1,4-bis- (2-pyridylmethyleneamino) -piperazine; (1,4-di (2-furoyl) piperazin-1-yl) piperazine, 1,4-bis- (3,4,5-trimethoxybenzylideneamino- Bis (2- (2-pyridinyl) ethyl) piperazine, 1,4-bis [2- (4-pyridinyl) ethyl] piperazine, (3-pyridinylmethyl) piperazine, 1- (ethoxycarbonylmethyl) piperazine, 2,3,5,6-tetrahydroxy-piperazine-1,4-dicar Diethyl 2,2 '- (piperazine-1,4-diyl) bis (2-oxoacetate); diethyl 2,2' - (2E, 2'E) -3,3 '- (piperazine-1,4-diyl) diacetate; dimethyl 3,3' (2-hydroxyphenyl) prop-2-en-1-one); 2,2 '- (piperazine-1,4-diyl) bis 2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) acetamide); 2,2 '- (piperazine- (Piperazine-1,4-diyl) bis (1- (9H-carbazol-9-yl) Propane-2-ol) fumarate, 3,3 '- (piperazine-1,4-diyl) bis (1-phenylpropan- 4,4'- (piperazine-1,4-diyl) bis (3-ethoxycyclobut-3-en-1,2-dione; piperazine- Di-tert-butyl-piperazine-2,5-dione, 1,4-didodecyl-piperazine, 1,4-dihexadecyl-piperazine, 1- 1- (3-pyridinylcarbonyl) piperazine, 1- (3-pyridinylcarbonyl) piperazine, 1- (R) -3-methyl-2-ketopiperazine; 4- (Boc-piperazin-l- (Piperazin-1, 4-diyl) bis (1-phenyl-1,4-diyl) Ethanol); 2,2 '- (piperazine-1,4-diyl) bis (2- Lt; / RTI > Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; Citric acid sesquipiperazine salt hydrate; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; Escropipate; 1-piperazine propanol; t-butyl-4- (2-amino-1-phenylethyl) piperazine carboxylate; Tert-butyl 4- [2- (aminomethyl) phenyl] piperazine-1-carboxylate; Tert-butyl 4- [5- (hydroxymethyl) pyrid-2-yl] piperazine-1-carboxylate; Tert-butyl 4- (3-aminobenzyl) piperazine-1-carboxylate; Tert-butyl 4- (4 - [(methylamino) methyl] phenyl) piperazine-1-carboxylate; Tert-butyl 4- (4-cyanopyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (5-formylpyrid-2-yl) piperazine-1-carboxylate; Tert-butyl 4- (oxetan-3-yl) piperazine-1-carboxylate; Tert-Butyl 4- (piperidin-3-yl) piperazine-1-carboxylate; Tert-butyl 4- (pyrrolidin-2-ylcarbonyl) piperazine-1-carboxylate; Tert-Butyl 4- (lH-pyrrolo [2,3-b] pyridin-4-yl) piperazine-1-carboxylate; 1- [2- (2,5-dimethyl-1H-pyrrol-1-yl) ethyl] piperazine; 1 - ((1,5-dimethyl-1H-pyrazol-4-yl) methyl) piperazine; L- (l-Ethyl-5-methyl-lH-pyrazol-4-ylmethyl) -piperazine; t-butyl 4- (2-amino-1- [4- (trifluoromethyl) phenyl] ethyl) piperazinecarboxylate; 3- (4-Fluoro-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3- (4-Hydroxy-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 3-furan-2-yl-piperazine-1-carboxylic acid tert-butyl ester; 3-thiophen-2-yl-piperazine-1-carboxylic acid benzyl ester; 4- (2-Amino-phenyl) -piperazine-1-carboxylic acid tert-butyl ester; 4- (2-aminoethyl) -1-boc-piperazine; 4- (5-Carboxy-pyridin-2-yl) -2-methyl-piperazine-1-carboxylic acid tert-butyl ester; 4-Boc-l- (6-methyl-2-pyridyl) piperazine; Fmoc-4-carboxymethyl-piperazine; Methyl 4-Boc-piperazine-2-carboxylate; N, N-dimethyl-1-piperazinesulfonamide; N-1-Boc-N-4-Fmoc-2-piperazinecarboxylic acid; N-4-Boc-N-1-cbz-2-piperazinecarboxylic acid; N-4-Boc-N-1-Fmoc-2-piperazineacetic acid; A sulfuric acid compound having piperazine-1-carboximidamide (1: 1); 1-ethyl-4-piperidin-4-yl-piperazine; 1-furan-2-ylmethyl-piperazine; L-Methyl-4- (2-piperidin-4-yl-ethyl) -piperazine; 1-Methyl-4- (6-aminopyridin-3-yl) piperazine; 1-Methyl-4- (piperidin-4-yl) -piperazine; 1-N-Boc-4- (Azetidin-3-yl) piperazine; 1-pyridin-2-ylmethyl-piperazine; 1-pyridin-3-ylmethyl-piperazine; 1 -thiazol-2-yl-piperazine; 2- (2,5-dimethoxy-phenyl) -piperazine; 2-carboxymethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; 2-ethoxycarbonylmethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester; L- (4-Methyl-cyclohexyl) -piperazine; L- (4-Methyl-piperidine-l-sulfonyl) -piperazine; L- (4-Trifluoromethyl-pyridin-2-yl) -piperazine; 1- (5-methyl-2-pyridinyl) piperazine; 1- (5-methyl-2-thiazolyl) -piperazine; 1- (5-nitropyridin-2-yl) piperazine; 1- (6-butoxy-2-pyridinyl) piperazine; 1- (6-methylpyrid-2-yl) piperazine; 1- (N-methylpiperidin-3-yl-methyl) piperazine; 1- (thien-2-ylacetyl) piperazine; 1-Boc-4- (piperidin-4-yl) -piperazine; 1-Boc-4-cyanomethylpiperazine; 1-cyclohex-3-enylmethyl-piperazine. ≪ / RTI > 18. The compound of claim 17, wherein the piperazine derivative is
(R) -piperazine-2-carboxylic acid; 1- (2-hydroxyethyl) piperazine; Piperazine-2,6-dione; 1- (2-aminoethyl) piperazine; 1,4-bis (2-hydroxyethyl) piperazine; 1,4-bis (acryloyl) piperazine; Piperazine-1-acetic acid tert-butyl ester; 1- (3-methylbenzyl) piperazine; 4- (Piperazine-1-carbonyl) -piperidine-l-carboxylic acid tert-butyl ester; Piperazine-1-carboxylic acid diethylamide; Piperazine-1-sulfonamide; Piperazine-2-carboxamide; 1,2-dimethyl-piperazine; 2-isobutyl-piperazine; 1- (2-pyrimidyl) piperazine; 1- (2-pyrazinyl) -piperazine; 1- (6-pyridazinyl) piperazine; 1- (3-hydroxyphenyl) piperazine; 1- (2-pyridyl) piperazine; 1- (4-methoxyphenyl) piperazine; 1- (4-pyridyl) piperazine; 1- (4-aminophenyl) piperazine; 1- (4-methoxybenzyl) piperazine; 1- (2-cyanophenyl) piperazine; 1- (2-methoxyethyl) piperazine; 1-Boc-Piperazine-2-carboxylic acid; 1- (2-ethoxyethyl) piperazine; (R) -l-Boc-piperazine-2-carboxylic acid; (R) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (R) -4-N-Boc-Piperazine-2-carboxylic acid; (S) -3-hydroxymethyl-piperazine-1-carboxylic acid tert-butyl ester; (S) -4-N-Boc-Piperazine-2-carboxylic acid; 1- (1-piperidinylsulfonyl) piperazine; 1- (2-diisopropylaminoethyl) piperazine; 1- (2-dipropylaminoethyl) -piperazine; 1- (2-ethoxyphenyl) piperazine; 1- (2-ethylbutanoyl) piperazine; 1- (2-isopropoxyethyl) piperazine; 1- (2-methylmercaptophenyl) piperazine; 1- (2-methylpropanoyl) -piperazine; 1- (2-morpholinoethyl) piperazine; 1- (2-piperidinoethyl) piperazine; 1- (2-pyrrolidinoethyl) piperazine; 1- (3-aminopropyl) piperazine; 1- (3-cyanopropyl) piperazine; 1- (3-diethylaminopropyl) piperazine; 1- (3-dipropylaminopropyl) -piperazine; 1- (3-methoxypropyl) -piperazine; 1- (3-morpholinopropyl) piperazine; 1- (3-piperidinopropyl) piperazine; 1- (3-pyrrolidinopropyl) piperazine; 1- (4-methoxybutyl) piperazine; 1- (4-pyridylmethyl) -piperazine; 1- (ethanesulfonyl) piperazine; 3-oxo-piperazine-2-carboxylic acid; 4-methylpiperazine-1-carboxylate; 1,4-bis (3-aminopropyl) piperazine; 1- [2- (2-hydroxyethoxy) ethyl] piperazine; 4- (5-Aminopyridin-2-yl) piperazine-1-carboxylic acid tert-butyl ester; 1- [2- (dimethylamino) ethyl] piperazine; 1- (1-methyl-4-piperidinyl) piperazine; 1-amino-4- (2-hydroxyethyl) piperazine; 1- (3-aminopropyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (dimethylamino) propyl] piperazine; 1- (4-aminobutyl) -4- (2-methoxyphenyl) piperazine; 1- [3- (1-piperidinylcarbonyl) -2-pyridinyl] piperazine; 1- (1H-Imidazol-2-ylmethyl) piperazine; 1- (2,6-dimethylpyridin-4-yl) piperazine; 1- (2-hydroxyethyl) -4-isopropyl-piperazine; 1- (2-Imidazol-1-yl-ethyl) -piperazine; L- (2-isocyano-ethyl) -4-methyl-piperazine; 1- (4-Ethoxy-pyridin-2-yl) -piperazine; 2-methylpiperazine; 2,6-dimethylpiperazine; Trans-2,5-dimethylpiperazine; 1,4-dimethylpiperazine; 1,4-bis (3-pyridinylmethyl) piperazine; 1- (ethoxycarbonylmethyl) piperazine; 2,3,5,6-Tetrahydroxy-piperazine-1,4-dicarbaldehyde; Dimethyl 3,3 '- (piperazine-1,4-diyl) dipropanoate; 2,2 '-( piperazine-1,4-diyl) < / RTI > 2,2 '- (piperazine-1,4-diyl) dipropanenitrile; (R) -3-methyl-2-ketopiperazine; 2,2 '- (Piperazine-1,4-diyl) bis (2-methylpropanenitrile); Piperazine-N, N'-bis (2-ethanesulfonic acid); 1-formylpiperazine; PIPES sodium salt; PIPES disodium salt; PIPES di-potassium salt; Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid); Ethyl 1-piperazinecarboxylate; POPSO disodium salt; 4-hydroxy-3-methoxyphenyl glycol hemipiperazinium salt; 4- (2-hydroxyethyl) piperazine-1-ethanesulfonic acid; 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid; HEPES sodium salt; N- (2-hydroxyethyl) piperazine-N ' - (4-butanesulfonic acid); 3-methyl-2-ketopiperazine; HEPES potassium salt; 3-piperazinopropionitrile; Ethyl piperazine acetates; And combinations thereof. ≪ RTI ID = 0.0 > A < / RTI > 18. The composition of claim 17 wherein the chemical additive is selected from the group consisting of mono-substituted 1- (2-aminoethyl) piperazine, bis-substituted 1,4-bis (3-aminopropyl) piperazine, ≪ / RTI > is a piperazine derivative selected from the group consisting of: 18. The system of claim 17, wherein the chemical additive is a salt of a cyanate selected from the group consisting of potassium cyanate, sodium cyanate, ammonium cyanate, alkylammonium cyanate, and combinations thereof. 18. The method of claim 17, wherein the chemical mechanical polishing (CMP) composition comprises
Corrosion inhibitors;
pH buffering agents;
Surfactants; And
A biocide (when the pH of the polishing composition is 5.0 to 8.0)
≪ / RTI > further comprising one or more of the following: